Before we start, I do want to recognize that the Safari/WebKit team are working hard, and I do desperately want them to succeed! Chromium's domination is bad for everybody, and building a popular browser that's focused on privacy & security, as they appear to be trying to do, is a fantastic goal. That does not mean their current approach deserves our blind support.
I think this paragraph better explains my feelings about Safari’s support for web features better than anything I’ve read in recent memory. Safari is not “the new IE” as some would paint it, but it does have the unique position as being “the browser that works different from the rest” for developers.
Ask someone why they think it’s good for Safari to be behind other browsers in implementing functionality and you’re sure to hear, “because only the Safari team cares about security.” As the author points out, that can be agued for some things, but a great many features Safari is missing have nothing to do with security, so that blanket defense doesn’t land.
For my part, I use Safari as my main browser on all my personal devices. I like its UI more than the competition, although the version 15 updates currently in beta are diminishing that lead for me. That said, I also manage several dev teams at work and Safari is constantly a reason we can’t do things we’d like to, sometimes because Safari does things differently, but more often because Safari simply doesn’t support it. And these are not security things at all, they’re CSS features that do some really nifty things we’d love to add in our software.
I don’t want to sound like a broken record, but this is another angle that annoys developers, which I think does long-term damage to Apple overall. Even the developers I work with who like Apple products and use iPhones and Macs, all agree Safari makes their web development life harder. Unlike the App Store where you can choose not to participate if you don’t like Apple’s terms, there’s really no way to responsibly make a website and not work around Safari.
If you hate that Chrome has such a large market share and want Safari to do better, I really think you should be in the camp that urges Safari to adopt web standards faster than they do today. Normal people don’t care about web standards, but they do care if their websites don’t load correctly (why my wife ditched Safari, for what it’s worth) and developers do care how easy it is to work with your browser.