I only partially agree.
We have parts in this game that are 10+ years old and it is starting to show.
Yes, they upgrade their engine and add new stuff, like the custom loadout feature, and this is great.
The thing is, you notice as a player that looks deeper than this, that some stuff didn’t change.
That this game isn’t on a 2020’s standard, but partially 2010’s standard.
Like no steering nose wheels, the MEC, the collision physics (and limits of those (so variable sweep wings, don’t change their hitbox, bc their one slot is tied up by the extracting gear), which they argue is from their engine, that they build and can change but this is another story), the map fidelity in air battles (just look at the ground textures, trees, houses etc, even with all the texture packs) and more.
Yes, lots of things got renewed (like they are finally working on DX 12) but also some important bits didn’t.
see above:
Because the game changed and adding stuff to an existing code base etc, while having compatibility to other things is way harder than writing it new.
This is why we have CS2, Planet Coaster 2, or completely new architectures, like GCN vs RDNA, not just upgrades from RDNA 1 to 2 to 3 etc
Because there comes a point where you have to rewrite everything to advance significantly.
To be clear, we haven’t reach this point, but you can see, that we get closer.
PS: also regarding implementing new vehicles, we are approaching a limit of kinda unique ones etc, which isn’t an issue now, but you can see, that we are approaching this issue, where there is now more copy pasta vehicles, leand and lease vehicles, and way less vehicles that are/were in service etc, that aren’t implemented.
Yes we have the South Korean (sub-)tree with unique vehicles, and Turkey etc, but adding Argentina with mostly British stuff is a thing, that hasn’t the attractiveness as adding the Italian vehicles had.