While Google’s Streetview cars were pretty nifty things, apparently the Streetview cars were not the source of house numbers in many countries. Instead, Google simply bought the rights to existing sources of information. National postal systems and municipalities had quietly created their own databases over the years.
People do volunteer to add house numbers to OpenStreetMap. My own city of half a million people got house numbers precisely because our local OSM club organized weekend outings where we would walk around town and add all the numbers. Then, when I moved out to the countryside, I would bicycle around to add all the house numbers for the surrounding villages.
theres the mozilla stumbler app that collects wifi ap's but I think the firefox app also collects the same thing unless you opt out. then there is opencellid as well.
i drove every road in my area capturing photos using mapillary with the end goal to use them to improve openstreetmap. i had the above apps running the whole time because why not. I'm sure other mappers do the same but if not I'm sure it would be easy enough to find a few people in most areas that would be willing to contribute
2) Android is a fucking awful mess: the whole thing is a single monolithic project that in general doesn't accept community contributions and is extremely difficult to build yourself. It's built expecting the user to be a danger to them self and handicaps them in ways that make it very difficult to run useful software. The devtools are pretty awful compared to what you have on GNU/Linux IMO, which is quite the achievement.
3) the people buying these phones are buying them because they don't want to deal with "polish" and are happy with something like debian or alpine.
4) there are almost no apps on android that are actually useful or can't be replaced with the companies web page or a small piece of (already available and much more mature) community maintained software that runs on debian. Youtube is an absolutely fantastic example of that, if I really want something native I have youtube-dl and ffplay. graphopper (the engine used on the librem5 for mapping) is arguably an improvement on google maps (except for geocoding heh. that's a different thing anyway and google's solution was to just pay people to drive around and collect house numbers which no one is probably going to volunteer for.)
5) f-droid is amazing compared to the play store but sucks compared to a real distribution package manager.