The only thing subjective here is the very first sentence. Everything else is either fact and enforced by the way DnD is designed or an example to illustrate said fact.

What exactly is subjective about the fact that DnD doesn’t have any depth or variety when it comes to anything besides combat?

Oh, and before you answer. Homebrew and cinematic encounters are not part of DnD as a system and using them in your argument will only strengthen my point.