Dexterity is not the issue. For Tekken it’s just knowledge and experience. There’s a ton to learn and practice. It’s huge. Much higher than stuff like street fighter. And I’m not talking about fancy tech. I mean the basic controls and move lists. You will not likely get to a point where you know everyone’s moves.

The reason to play fighting games is strictly that you like the idea of honing the skill and playing competitive 1v1 matches to improve. Progression and reward is pretty different from other genres in this sense.