> It's getting dangerously close to the modern day I.E.

This line gets thrown around a lot, but if you look at the supported features, Safari is honestly pretty up-to-date on the actual ratified web standards.

What it doesn't tend to do is implement a bunch of the (often ad-tech focused) drafts Google keeps trying to push through the standards committee

I would agree, except for CSS. You still see checks for webkit in CSS fairly regularly.