I just read this earlier this year as my introduction to Vonnegut and thought it was great satire and tone, OP said. It definitely encouraged me to keep exploring other books by him, and I just checked Slaughterhouse 5 out from the library!
For me How High We Go in the Dark by Sequoia Nagamatsu and Kindred by Octavia Butler. Both were the kind of book where I finished and just needed to stare into the distance and process for a while, I don’t think I’ll be emotionally ready to read them again any time soon but I’m certain I’ll revisit them at some point.
My local library puts out a lot of great recommendation lists (like at least 2 per month, one generic and one themed across different age ranges), and most of the books on there are recent (and new to me at least) and they tend to choose some that aren’t as hyped up in other places. I’ve really enjoyed some books I’ve gotten from those lists!
I almost never DNF (and usually if I do, I pick it back up a year later and finish it) but I certainly don’t think it’s bad to do so–I just have a hard time giving up on a book myself but it does mean I’ve wasted some time. Part of why I don’t DNF is because I don’t usually pick up books totally blind, not that I know everything about the plot but I look up reviews/type/moods on Storygraph and Goodreads to see if it will match my tastes, and because I’m always worried that the second half/ending will redeem it (which has happened, but rarely). But I also don’t read just one book at a time, so if I’m not into it, I’ll put it down for a couple of days or weeks while I read something more fast or enjoyable to stop me from ending up in a reading slump because I’m not super into a book.