Safari definitely does not just follow suit (see https://caniuse.com/?compare=chrome+102,safari+15.5&compareC... for example).
Many of those features can be used to comprehensively fingerprint your device allowing advertisers to track you across sites even without cookies. Forget about any laws or privacy efforts it would all be moot. And many of us value privacy far too much.
Apple even implemented the "do not track" API and advertisers completely ignored it.
Call me when I can install Safari on linux (or any platform other than macOS/iOS).
Until then - the ugly truth is that Apple intentionally underfunds and underdevelops the browser because they see it as a fundamental risk to their control and revenue from the App store.
It's there because "they have to have a browser" not because they're doing anything novel or clever. And many of the things they refuse to implement aren't related to ads or Google's control at all - they're things that would have narrowed the gap between what a website can do on iOS, and what the App store apps could do.
Again - Apple is acting EXACTLY like microsoft here. Underinvesting in the browser because they see it as a fundamental risk to their best revenue stream - much like how MS ignored IE when the focus was all on local apps (the king of which was still MS office).
That's not a truth that's an opinion. And one I would definitely disagree with.
When it comes to speed, privacy and battery life I am always choosing Safari over Chrome. And many of us care about those three things over new features that often just make the web worse.
I disagree that Apple is underinvesting: their slower, more deliberate pace can be an advantage: you can see the pitfalls of implementations in other browsers. I am not disagreeing that Apple has had their own share of bugs, though.
Where things went off the rails was the things Microsoft refused to implement due to their monopoly position. They had a binary component architecture, but it wasn't sufficient to run Java. They had Java, but it was a vestigial and crippled version. Their HTML/CSS engine was just "odd", incompatible not only with emerging standards but with any published standard at all.
Basically "the problem" with IE wasn't that Microsoft "did whatever it wants", it was that it did (or didn't do) very specific things intended to prevent users from wanting to use IE at all, in a vain attempt to favor desktop applications or IE-specific implementations.
These APIs are one of the big areas where chrome/google have tried to expand the remit of what's possible with web apps, for example the file system api can be used by a web app to access files directly on a users machine.
I do use a MBP daily, and the software there is amazing. But seeing that their software barely works outside of their platform, it's a miracle they have any customers at all.
I don't think very many of their customers run any of their software anywhere other than on Macs and iDevices, so I expect that doesn't have much effect. Aside from the apple TV app on Roku and various TV operating systems and such. And still, none of this makes Safari not an "actual browser".