People have different priority, most end user gives no fuck about the pile of garbage APIs that just keeps growing in modern browsers, they just wanna read some stuff. When developers cry about their "api", some kid in africa isn't able to access knowledge on ther internet because sites have to use look behind or whatever.
Personally I find Safari a great browser on iOS and prefer not to add to the test matrix burden with different browser engines on iOS. Also this restriction is the only thing keeping Chrome from dominating the future of Web, who can't be trusted to not use it as an anti competitive weapon as we've seen with AMP.
And in Safari there's zero visibility into why things break, they just silently don't work. At least Chrome is pretty good (in my experience) about throwing an exception or at least logging warnings to the console
Is it really as bad as the IE days though? I didn’t work on web back then, but these days if I run into a safari comparability issue, the workaround is usually pretty painless.
At least in the IE days everyone _knew_ IE was a problem, so we were looking for a solution as a community. Now? We comments that are dismissive of crap instead of inspiring towards quality.
But it's not really a polyfill, just a library.
Say what you want but it is so frustrating when you run into problems like this. It does remind me of old IE days where we had to produce one gazillion hacks for IE.