Yeah, but some amount of the time is just easier to rely on the user agent. Why bother with the fancy logic when user agent spoofing, adblocking Firefox users is a % of a % of a %?
I tend to agree. I think there's little need as a developer to go that extra mile for accurate browser detection without UA unless it's for fingerprinting. Most feature sets are supported and where it isn't you have a polyfil or whatever shim to make it work. So in the case of fingerprinting you try not to rely fully on anything the user can alter easily.
I won't spoof the agent. I want Google to know I'll keep using Firefox no matter what. Except for YouTube, I don't use any other service of theirs, too shitty.
The best way to make them back down is to show we won't bow.
The other day, I finally switched to ProtonMail. I still just forward my gmail inbox for now because I'm too lazy to go through all my accounts and change the email all at once. In due time, I will have switched. Fuck Google.