I adore The Evil Within 1 & 2. I could write an essay here on either game as they're kinda' both fascinating in their design, but I'll try to keep it brief.
Both are HUGE love it/hate it games, some of the most divisive games I've ever seen. Even moreso, they're divisive to each other. I know some people who LOVED The Evil Within 1, but ended up HATING the second game, as well as people who HATED the first game, but LOVED The Evil Within 2. I think it's telling these games strike such a huge reaction out of people though, like some of the people who love these games or one of them LOVE it, and some who hate these games or one of them HATE it. They're not dull games and they definitely seem to get quite a reaction out of people.
I loved both of them, but for very different reasons. However, I admit to having very broad tastes in horror, both games itched different things for me. Both games pull from a lot of horror films and games, but they end up not being like any other game out there.
Honestly, I say they're 100% worth playing because at the very least they are rather unique and interesting, and you'll hear opinions all over the spectrum on these two games to really be able to trust any sorta' unified opinion, some will one or the other is great/terrible. Some will go as far to say one or the other are some of the best horror games ever or top games of the generation, while others will be middled, or others say it's bad, and the placement of both titles may radically be different per person. If you have any interest, it's kinda' just worth playing through them and forming your own thoughts.
However, I also will throw out there that Kidman's 2-part DLC for The Evil Within 1, The Assignment and The Consequence, are both underlooked by many sometimes and are actually worth checking out if you're doing a series playthrough. They're different than TEW1 & TEW2 with it's own flavor and focus, but provides a 4-6 hour campaign that I think will end up as some people's favorite part of TEW experience (but like all things TEW, opinions on it are divisive).