Given that Chrome isn't shipping ActiveX or Flash, what's the issue? Apple and Mozilla decide how (or if) they want to implement each standard. If there's no demand for the feature, it shouldn't be a problem ignoring it. If icky features like WebUSB and Bluetooth are terrible, users won't notice anyways.
I've daily-drove Firefox for close to 5 years now, but Chromium is simply better-developed in a lot of ways. It integrates better on Linux and doesn't ship with annoying adware that nags you with pop-up modals. I don't want Google's browser engine to be the best, but I don't think I'd be using Firefox today even ignoring compatibility concerns. Safari isn't even an option to me, not that I'd willingly pick WebKit anyways.
> And yes, "only works in Chrome" is a frequent enough appearance to warrant a worry.
Crocodile tears coming from an ecosystem where "only works on iOS" and "only works on Mac" is the default. Apple is not the savior of the free web, and if the openness of the internet relies on their goodwill then it is already lost.
Google's strategy is pressuring Apple to make more capable software. When a user has more freedom in a browser than they do in their hardware's native runtime, something is gravely wrong (and you can't blame the browser).