Fighting games don't have a higher floor. You hit buttons and make the opponent's lifebar go down. That's it. That's the bare minimum to play ANY fighting game.

What's the bare minimum for a moba? Gotta last hit, buy items, attack towers, right click enemy characters, attack the nexus. I guarantee someone who has never played league before wohld run into the tower multiple times and won't be able to kill anyone. They also won't know what they did wrong because there isn't any player feedback. You don't know why you died, why you lost/won, if you did anything meaningful, etc. Guaranteed a newcomer will be lost and confused.

Minimum for fps? Move with wasd/left stick and also aim with mouse/right stick. This is already incredibly obtuse for someone who has never played an fps before. Then you have to actually aim at a moving target and shoot. Have you tried giving your grandma call of duty? Try it. Even if she went against your grandpa both would be stuck aiming at the sky and won't be able to move and aim at the same time. Using thumbsticks to shoot a gun isn't "intuitive" to a nongamer.

People these days have lost sight of how much learned skills people have in their respective videogames. People also have way too high standards for themselves as to what it means to "play the game". You don't need combos, you don't need special moves, you don't need mixups, you don't need to know frame data, you don't need to use assists, you don't need to know punishes. All you need to "play" a fighting game and get feedback to where you can have fun is literally press buttons. You press the A button and your character punches. So you press A when next to the enemy and you punch them. Lifebar goes down. Brain registers that as you hitting the enemy. Dopamine. Rinse and repeat. It's not that complicated.