I came to give you a deeply disappointing answer. That answer was "There is no game".
Thinking about that answer, I'm going to amend it. The answer is thus: "The Game You Like The Most".
The reason why is that you're going to pour time and time into it whether you are wrecked or not. You will do what you can to learn about it. You will research moves and try to execute them yourself because it's fun for you. Work is only Work when there's no passion behind the effort.
Take the games you just mentioned. They couldn't be more different than each other. Tekken 7 to me is the most complicated of the three. Dodging out of the way, using the entire stage to your benefit, realizing you can only get the best combos on certain stages doing certain moves on certain bodies requires such a deep knowledge of the game that it's staggering to most people who come from "Aim reticle until object dies"
Mortal Kombat 11 might as well be a spin off game compared to the rest. But that's actually par for the course in Mortal Kombat Games. No two play exactly alike. Meter is thought of differently. You have more defensive options than ever game you mentioned. And each character has the chance for an ingrained mechanic that is special to only that character. E.g. Jax's heat-up arms.
SF5 is admittedly my least favorite of these games. I have it, and it's an easier version of the series than I've ever played (Sf 3rd strike will forever be my favorite fighting game of all time). Each Character's special ability are triggers and another meter you need to measure. But it plays vastly different than MK 11 or Tekken. The concept is the same, outthink your opponent. But the tools to do that are vast between the games.
Find the game that moves you. Find the character that sings to you. And get ready to lose. Lose like you never did before. But use every game to build knowledge. Hey, you might like how Ryu's Roundhouse looks, but it's too slow for a reliable anti-air. Ok, You've heard good things about His standing close jab. Time to invest some practice in that.
Try to find people even here that has the same game. Get in some matches. Talk afterwards. Theory-Craft. Above all, Have. Fun. It doesn't matter if you lose. This is our hobby. Just find enjoyment with whatever you decide on.