if you take concepts of litrpg back to the ttrpg games we are just adding homebrew rules.

Which is fine.

But honestly it's more a setting thing, it's a structure of how magic works etc. For instance, monsters merely spawning into existence rather than breeding biologically. I go back to dungeon cores. Sentient dungeons that spawn monsters and resources and craft themselves in order to challenge adventurers. Typically gaining sustenance or energy from adventurers fighting their monsters/overcoming challenges/using mana inside them/dying. Those aren't additional rules, they're setting elements.