Microsoft Flight Simulator has had the entire world since at least version 5 (1993). But if you mean that it's the first time it has real satellite data for the whole world then yeah, it's a huge leap in out-of-the-box quality and it's nice that for once, you don't necessarily need to download scenery mods.
Sure you wouldn’t have to. But then you’d end up with a product where the canonical experience is hidden behind hours of tedious 3rd party mod management.
Plenty of games (and other software products, I’m looking at you Atlassian) end up in this purgatory, where the existence of good enough 3rd party mods remove the incentive for the devs to implement the features themselves, and the user just ends up having to navigate the maze of mod management to get the experience they want. The example I mentioned, Cities: Skylines, is a perfect example of this. There’s a number of 3rd party mods you have to install to get that game working properly. On top of that updates break the mods every so often. The reason I no longer play that game is that one day I logged in and a mod wasn’t working, I couldn’t be bothered trying to fix it, so I just never logged in again.
FS2020 is a game that would obviously be very easy to continually improve over time. If a majority of those improvements end up hidden behind a tedious mod management system I’d be very disappointed.
Ah sorry, I see what you mean now. Yeah absolutely it would be an improvement on previous releases if there's a method for community content to be added to the base game, getting the improvements out to everyone automatically.
I don't know of any custom specific building models in the game right now, not even ones by the dev team. It's all either the photogrammetry 3D that's in a few hundred cities, or the AI generic models (which are a mix of pre-made generic buildings, and generated meshes for custom shapes).