Earlier quoted context omitted.
There's still plenty of web sites that check the OS and if it's not Mac OS, Windows, or Andoid it's no service for you. Faking your UA is not always about privacy, it's about defeating stupidity.
The only websites that really do this anymore are ones that are delivering native code for those platforms or those that require DRM that only work on those platforms.
But well, I haven't had to spoof my browser's UA for a few years. If some site refuses it, I'll just move on. (Including some that started doing it after I brought thousands of dollars worth of stuff from them.)