REAL TIME BATTLE

QUESTION: why don't game makers create more of this type of game.
Why are MOST games Party driven ??

If you're asking about the professional game development industry at large, that's an interesting question that probably has a very complicated answer...if your underlying premise is even true.

If you're talking about indy amateur game devs in this particular meta-community, the answer is much simpler: the toolsets we have for making RPGs are better adapted and more robust than the toolsets we have for making action-adventure games.