X probably stands for the idea of his “everything app”.

I self-host a Bitwarden instance at home. Passwords are sensitive data, which I do not want to put onto any cloud, where I do not have control over them. I know E2EE is a thing. However, I still have more control with self-hosting. Additionally, E2EE means nothing to me if the client application is proprietary (most password managers are, unfortunately).

Well, it’s OpenStreetMap, you can basically tag anything. Although I’ve never seen something like a dedicated flag disposal here in Europe, you could combine amenity=waste_basket + waste=flags.

waste=flags is only used twice to this date, however. See taginfo.

How this data is used, however, is up to the renderers/data consumers.