@merthyr1831 It comes down to preference, how efficient you want to be and what best supports the end goal of the result. There’s really no general purpose answer.
You can even have n-gons in subdivision surface models if it’s a flat area.
@merthyr1831 It really depends what the final mesh is going to be used for. If you’re just rendering in Blender multiple meshes are fine because the renderer will take care of most things and it’s modular. Game? That gets complicated fast. For a prototype it may be OK but for production, you want to control overdraw and polys and bake the multiple meshes down to a game ready monolithic model. A tank in a game is going to be multiple meshes to some degree. Modular supports variations.
@Nibodhika @dbat Steam did the exact same thing when it was new when they would say “If Steam ever shuts down, we’ll give you perpetual licenses to the games in your game library.” Probably around the same time in their existence as GOG hyping DRM-free.