> What non standard API only Chrome implements and evil web developers want to use?
Two things:
1. Feel free to look at the wide litany of garbage security and privacy holes Google has added to Chrome that are only supported by Chrome forks, which Mozilla and Safari have both publicly declared they will not support.
https://mozilla.github.io/standards-positions/
Mozilla has defined 24 items as "harmful", and that's a good start at bad ideas Google has shoehorned into calling "the web". Who wrote... basically every single harmful spec? Oh, the adtech company that is allowed to also make a web browser.
2. You're also just not understanding the problem. It doesn't actually matter what web developers want to use and don't want to use. Web developers are, and I'm sorry to insult a bunch of HN users here, really lazy. If they can demand people switch to Chrome, they will. In fact, they often do even when the website works fine everywhere else.
Next time you hit a Chrome-only user-agent check in Firefox, tell your browser to lie about the user agent and you'll probably discover the site works fine. I constantly see companies tell us their products "aren't supported" unless you use Chrome, even if they work fine in Firefox, and the issues we call about aren't caused by the browser, and can be duplicated in Chrome.
Right now, the only reason far more web developers aren't pasting Chromium checks into every single page, is they have to support Safari anyways, because they can't lose the iOS market. But as soon as it's possible for web devs to force users to install Chrome to continue on iOS, they will. And at that point, Google really doesn't need to pretend it cares about web standards anymore anyways, because alternative engines will already be dead.