Arguably, Safari is the IE of our times.
Safari somehow always have rendering issues. I use Firefox as that's closest to standards, I hate bending standard code to fit a garbage browser's special needs.
But yes, Safari is slow in implementing new features a bit and it does get annoying from time to time. But it's nowhere near the IE hell from ~2000 - 2008.
Then you bring macOS into play, and the way Safari on mobile syncs with Safari on desktop is really nice. Password sharing in particular is great, so you end up getting sucked in to Safari!