Yup, just like during the bad old days of Internet Explorer's dominance. I remember encountering websites that only worked on the Windows version of Internet Explorer as late as 2006. We had a nice time in the late 2000s and early 2010s when web developers coded against standards instead of against the market-leading web browser. There was competition between Firefox, Opera, Safari, and a revitalized Internet Explorer. I don't remember IE 7 and later being that bad, though by then I had switched to Firefox on Linux/Windows and Safari on Macs.

Then came an upstart web browser from Google named Chrome....and now we're back to the bad old days of web developers coding to the dominant web browser again.

Yes. These days if a site is broken in Safari there's a ~70% chance it's broken or degraded in Firefox too.