Hell no. Lost Legacy shits all over Uncharted 4. The story, characters including Nadine because she's actually worth being in Lost Legacy where as in Uncharted 4, she's not needed at all (and Sam for that matter) are far better than Uncharted 4. Pacing in chapter 4 is NOT an issue because you can ignore the side content completely where as the pacing issues in Uncharted 4 is throughout the entire game and nothing can be done about it.
The only Uncharted game that is worse than Uncharted 4 is the original Uncharted and even then, I gave both the same 8.5/10 rating. Will never understand all the praise that Uncharted 4 gets especially over Lost Legacy when Lost Legacy is by far the better game for one main reason - unlike Uncharted 4, Lost Legacy is all about going on an Indiana Jones type action packed adventure which is what the franchise is supposed to be. Uncharted 4 is the lone game that doesn't feel or play like this at all. UGH.
The story in The Lost Legacy is half-baked. I've just recently replayed the series and it's glaringly obvious that not much was done in that department. Nadine is horrible in The Lost Legacy. While she was misused in Uncharted 4, mainly due to the ending of her character, she's at least positioned interestingly as a war criminal serving as the hired muscle for the main villain. She overwhelms you twice, you get just enough characterization, but she doesn't get her comeuppance at the end because for some reason, the writers thought it would be better to use her to drive home the point of a certain theme, which obviously is unsatisfying considering we're dealing with a legit horrible person in universe. That and the fact that she's ultimately a minor character, so using her for this is bizarre. She was basically the hired muscle role we tend with in previous games, but they didn't give us a firm resolution, and kind of let her get away with it. It's subversion for the sake of subversion, which is bad.
In The Lost Legacy, she is basically Chloe's sidepiece. She's there to bring up story points for Chloe's character when necessary. Her character, despite spending 7 hours with her, remains without any substance. There's like two conversations that basically involve her saying Shoreline was her father's company and that's why it means a lot to her, but aside from that, she's just a nothing character. It's worse because despite Chloe's story being half-baked, she's a legitimately charismatic lead but has nothing to really play off. Nadine is just kind of a drone there to bring up "story" when necessary. What makes it worse is that The Lost Legacy is clearly attempting to redeem Nadine's character, and that doesn't work when we're dealing with what is a huge piece of crap in universe. You can't just do a half-assed about turn with her. It rings hollow because it is. And even in Chloe's case, they take the least interesting route by having her past relegated to about four brief conversations. The story itself has no depth whatsoever. There's an inkling of it, but the game isn't really interested in exploring it all in any meaningful way. (Probably because it was originally DLC.) It's just a lot of banter, half of which is somewhat bad, until Sam gets involved. Sam himself seems kind of off compared to his UC4 incarnation, and just seems like he's there to crack jokes. His inclusion is superfluous whereas he's a pretty major component in UC4 and that games uses that time well to flesh out his character and relationship with Drake. Asav could've been a great villain in a proper game, but The Lost Legacy does the bare minimum. Not a bad thing considering the original trilogy, but he has the potential to be really great, and it's kind of wasted, because again, the story is half-baked.
Also, Chapter 4 is terrible regardless of not doing the side content. I've never done it and it just grinds everything to a halt. The Lost Legacy obviously started out as DLC, and it very evidently shows in the game itself. UC4 is a big step up from previous games when it comes to storytelling and general presentation, and it's jarring when you go from that to The Lost Legacy after it. Even simple stuff like the openings demonstrate a big difference in quality in terms of how the presentation is. That's ignoring the general quality of the set-up, the character interactions and relationships, and how it handles its themes. The Lost Legacy barely even has a theme. It's basically a quick adventure.
UC4 gets the praise it does because it's a pretty fantastic game. It takes its time, does a great job of giving its main characters depth, and the story feels plenty fleshed out because they actually do a good job of exploring the main themes and relationships. Even the "pacing" criticism feels odd to most people that like it because the game is a send off for Drake, and the story takes its time to set things up, and then pay them off really well. It would be like arguing The Last of Us had bad pacing because it takes a few hours to set things up and has a slow start. There's a reason behind that. The only flaws I could levy at the game would be that it felt we needed another 2-3 combat arenas because the gunplay is a huge step up, but the game doesn't quite hit the right balance. Another set-piece would've also been welcome. Again, for the balance factor. When you have a game in the series that was essentially perfect (Uncharted 2), it's a little disappointing that Uncharted 4 came incredibly close to matching that kind of perfection but has a few odd things holding it back. Everything else is mostly on point aside from the resolution of Nadine's character. The story, characters, game-play, and yes, even the pacing, is pretty great overall. It feels like a pretty epic resolution for the most part. And Drake is simply a fantastic lead.
The Lost Legacy is let down by a half-baked story, and the only reason why that factor doesn't stand out much, is because the game is less than 7 hours long. You can pretty much just zoom through it with only Chapter 4 feeling like a drag. And just like UC4, The Lost Legacy takes a few chapters to get going, but in its case, those few chapters are almost half the game. Whereas with UC4, it's basically the first 2-3 hours of a 15 hour game (and the opening in UC4 is way stronger anyway which alleviates that subsequent 2 hours of set-up). TLL does a good job of throwing in a bunch of combat encounters and some puzzles later on which really helps redeem the earlier weaknesses, but overall, it feels very much like a side game and is very lacking in comparison to UC4. The one great thing it does is that it does justice to Chloe because UC3 didn't do much with her, and UC4 basically ignored her since obviously, the story wouldn't really work with throwing her in it. And really, if anything, a Drake and Chloe game is something that clearly needed to be made.