what do you expect from a free browser?
And Chrome for Windows (or any browser, for that matter) is paid? Not sure what kind of argument are you trying to make here.
maybe they put their effort on where the money came from the most... btw Linux Device Driver is an interesting subject, why device manufacturers havent catch up since few decades ago? maybe due to ecosystem. like most photographers they rely heavily on Photoshop et al and those are Windows only. so they need a printer that can work in Windows. since very minor users are on Linux maybe its not the effort to develop and maintain dual OS driver.
Nonsense. This has most likely zero to do with neither Linux nor Firefox. Both Firefox and Linux have no issues with sound, heck even Google's Widevine DRM (e.g. used by Netflix and many others) works in Linux and Firefox.
These kinds of browser compatibility issues are in 99% of cases caused by lazy web developers that either don't bother to test on anything except Chrome and then leave in Chrome/Windows-specific stuff that breaks elsewhere. Or even outright hardwire a user agent check in the website and refuse to even attempt to work unless the browser identifies as Chrome. Often simply bypassing the check using a debugger makes the webpage work fine, surprise ... This doesn't screw over only Linux/Firefox users but also Mac users with Safari, mobile browsers, screen readers for the blind, etc.
It is the good old Microsoft Internet Explorer being mandatory for many sites for no other reason than the web developers not bothering to develop for an actual W3C standard but only for MSIE all over again. And with the same stupid arguments about marketshare, snarky comments about minority operating systems "that nobody uses" and so on.
E.g. we have a large supermarket chain here where they have put some buggy advertising/tracking code into their online order website causing my Firefox tab to literally spin up the CPU in cycles and hang. No such problem if I open the offending page in Chrome. Newspaper website I go often to is broken in Firefox because some dumbass didn't bother with standard CSS styles but they have hardwired some Chrome-specific code. And many other examples ...