I mean some of these changes are excellent... like the ability to use your own non-WebKit/Safari browser.
2) The main market effect is probably gonna be that Google is able to cross-promote and "whoopsie" bugs its way into having even more market share for its engine. Don't love that, but it won't personally harm me unless Safari market share gets low enough that dev shops drop from "test on Chrome and Safari" to "test on Chrome... and that's it".
3) Where this might really, really suck is if they have to permit non-browsers to bundle Web and/or JS engines. I very much do not want that and it's likely to make my experience noticeably worse, if that happens. Dunno if that's required by the changes, though.
As far as tracking/privacy, I suspect Apple's next move would be to provide greater restriction of your device information and browsing information secure (another win for customers that isn't really granularly provided today).
But yes, that is a good change that should have happened a long time ago. Same with the game streaming one.
Aren't you just describing... competition?
If Apple's browser product is superior, users will use it. If those users want a feature Chrome has, Apple can either implement the feature or ignore it. That's no different than things are today, if you wanted to avoid a Chrome hegemony then we should have invested in a better cross-platform delivery mechanism than Electron. We didn't get one.
Apple's support to WebKit and Safari is entirely compulsory. I agree that it's a positive impact on the web as a Firefox user, but I'd also argue Apple's ends did not justify their means. The development of Safari is very distinctly neglected to increase demand for native (read: taxable) APIs.
Competition in this space is great but Google has far too much control of the browser market for my comfort and we are seeing the harm of that with third party cookies, tracking, AMP, and other things.
And again I welcome this particular change, I am just worried about what it will mean as Google pushes harder.
It'll be different regulation that comes for Google, but you can take solemn certainty in knowing they're up next. My biggest concern is that Microsoft won't receive enough scrutiny, but on the other hand I can barely trust them not to capsize Windows over the next decade.
Regardless, 10 years from now I hope we'll have a more competitive and vibrant future for local compute and the web. It's a shame (but not unexpected) that regulation has to draw the line.