Geoguesser is now an esport, somehow.
It's pretty crazy. Strategies include memorizing the more obvious stuff like which side of the road you drive on or style of the pavement markers, but also some dumber things like recognizing the car taking the pictures because the google guy in that country has a shitty camera.
https://geohints.com/
As someone who's played Geoguessr for a few years now, I'd say there are 3 levels of knowledge:
1. Guessing the country/location based on real life knowledge like language, architecture, climate, signs, landscape, what the blurry people look like etc.
2. Learning the street view specific meta-knowledge that you speak of, like camera generation, blurry pieces of google car, a police car following you or artifacts in the sky, plus the relatively simple things that normal people don't know, like Brazilian traffic signs having a black back, specific bollards or license plate colors. Most of the content of the Geohints site basically.
I'm at maybe 30% of this level without ever trying too much, which gets me to sort of an "ok casual" level. However even knowing 100% of this will not get you to the level these guys are at. For that they need to:
3. Learn minute details of various regions mostly on their own, though there are some super specialized in-depth guides for some countries circulating online. This could mean remembering all the regional postal codes in Philippines ("pro" people actually do this), but mostly it means recognizing the differences in regional flora, topsoil, landscape, road quality, architecture or whatever else available that are pretty much invisible for a normal person. Some people try to create a system and consciously learn and remember things, some people just play a ton and get a feeling for each area.
This is the level that's shown above and that's beyond understanding for me.
It's a really fun game though.