Thanks, I looked at these colors for so long that they "appear" normal for me. Some are about "perception", night life is not necessarily good when you want to live in the place but is fun when you come for visiting ("activity"). However, I admit that this is not clear and needs work.
The coverage is larger part of Europe, gaps are present where there are no data points, where OSM coverage is practically zero. Aremenia looks like it's on a cut off border of OSM Europe file that's the source of everything here, only points close to the border are available.
Exactly this. And the European case is the opposite starting point. Paris already had 2+ million people when the Metro opened in 1900. You're not building rail to create land value, you're building it because the existing density already demands it. Which is why European systems basically all require public subsidy while the Japanese private lines could turn a profit. The preconditions are just so different that copying either model somewhere else rarely works. IME the people pushing "just do what Tokyo does" tend to skip over this part.
The coverage is larger part of Europe, gaps are present where there are no data points, where OSM coverage is practically zero. Aremenia looks like it's on a cut off border of OSM Europe file that's the source of everything here, only points close to the border are available.