zlacker

What are these websites ?

Search - I don't really see a browser specific optimization potential here.

YouTube is probably mostly app based on mobile.

Gmail and other gsuite apps are also app based on mobile.

I'd be surprised if they cared about mobile Safari support in those much or if it played a big factor.

>>moonch+(OP)
Here's just one example that I can remember of Google Search doing UA sniffing to serve a worse experience to Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=975444

>>moonch+(OP)
All 3 of those sites heavily promoted Chrome to users of other browsers, inaccurately claiming that the service would be better with it (it wasn't).

YouTube also had an interesting example of the problem: they shipped some code using Chrome's early draft of what became Web Components. Firefox and Safari implemented the standard version, but there was a LONG period where YouTube used a very slow polyfill instead of upgrading to the standard version, causing Chrome to appear to be faster because it wasn't all of that extra JavaScript. If YouTube was an independent company they would likely have fixed a poor user experience much faster.