I remember being really worried about ARR being a slog before I bit the bullet and bought the game. But honestly, I took my time and went full casual for the leveling, and it wasn't nearly as bad as people were saying. Sure, if you're absolutely dead-set on getting to the GOOD stuff ASAP (Heavensward), then yeah, it's going to feel like it's taking forever. But I actually felt like Stormblood had a less interesting story than ARR. I know it's a lot of buildup for future payoff, and there were a few really cool parts (mostly in the post patches) but I just couldn't give less of a crap about the Far East, and Zenos has been the most uninteresting villain in the game thus far, imo. And don't even get me started on Lyse...
But I digress, do NOT skip ARR. I know it's really tempting, but there is important story, character and world building in 2.0 that makes later story points mean so much more. Also, the 2.5 finale was jaw-dropping for me. Going into Heavensward without experiencing it really lessens the impact of that expansion.
Just a little anecdote, I remember seeing a commercial for Shadowbringers in the theater before Spider-Man: Far From Home, and I was just sitting there thinking how epic it looked, wishing I could feel that way about WOW again (haven't had that feeling since...probably Wrath, and I'd been playing it non-stop for 15 years). Fast forward 8 months, and I'm just NOW working my way through Shadowbringers. I don't regret taking so much time to get here. Aside from having to force my way through half of Stormblood, it has all been a joy. I also like to take my time once I get to the end of each expansion and thoroughly experience each one's endgame, which is totally possible with the Duty-Finder. All content remains relevant, which is another thing I love about the game.