But to answer your specific question, regardless of whether it's needed or not, it's mandatory. https://www.whitehouse.gov/sites/whitehouse.gov/files/omb/me... requirement #2
There’s even an open source project around the public analytics.usa.gov dashboard:
There is nothing special about visitors to .gov websites vs any other major website. You stop supporting old browsers when their installed base gets small enough; this has nothing to do with analytics or those specific sites under surveillance.
Finally, you’re also wrong about how sites use analytics: global stats don’t matter much compared to your actual visitors, whose demographics can vary significantly. Every site I’ve worked on since the mid-90s has found that to be important enough to do basic analytics of the sit under discussion here.
Calling it analytics doesn’t make it not mass surveillance.
It’s not okay when either group does it. I’m surprised to see that “the government should not spy on its citizens” is such a controversial belief.