Look at every other successful fighting game franchise, SF, Tekken, etc; they all improve on each predecessor. Ryu is Sf6 is familiar to Ryu in SF5. They dont ask questions like "what if Ryu was actually Ken in this timeline" because they don't throw out what has worked for them for 30 years. The Result? Each game generally feels like a more complete and refined version of it's predecessor. They built on the foundations they worked hard to establish, instead of constantly starting from scratch. Ok, I get it, Mortal Kombat is different, fans WANT some change to some extent, but i think it goes too far in the opposite direction, NRS games don't feel like they improve, because none of their good decisions stayed. Let me explain what I am rambling about with some examples:
Lets start out with MK installments as a whole
MK9 - a fan favorite that arguably saved the franchise, and most of this is because it took what people loved about the first 3 games, and IMPROVED on them. The gameplay isnt balanced, and the animations were terrible, but is still layed out a strong foundation.
MKX - The game that got me into this franchise, great atmosphere, and fast paced, exhilarating gameplay. The variations system was probably my favorite gimmick of the NRS era games. Despite my nostalgia, this game had flaws that can't be ignored, it had too little focus on neutral, a weak roster, a ugly color scheme, and excessive 50/50s.
MK11- A perfect example of a "sidegrade", it does many things better then MKX, but also many things worse. Neutral is fun, graphics are top-notch, the roster is better, Brutalities and fatalities are arguably better then mk1. Despite this, it has neutered combos, terrible meter mechanics, annoying poke/throw meta, and the custom variation system felt worse than MKX's fixed variations. They tried too hard to fix MKX's mistakes, and ended up throwing away aspects of gameplay that should have stayed.
MK1- Same with MK11, a sidegrade. I prefer this one over MK11 because it has genuinely fun combos and good meter mechanics, but everything else is lackluster. Animations feel really outdated compared to other modern titles like Tekken 8 and SF6. Kung Lao in MKX and MK11 felt like a real fighter, Kung Lao in Mk1 fights like a white guy doing a racist impression of a Shaolin Monk. Scorpion as Kuai Liang? Look, id respect it if they actually committed to it and gave a sub-zero twist to his gameplay. What if he used a fire ax like Kuai Liangs ice ax from mk11? What if he borrowed sub zero's strings from previous games? What if he could summon fire clones? Instead, they just made him...boring. Nobody asked for Kameos. Nobody asked for Shao to have an Ax. I think you get my point, there's too much change for the sake of change, and none of their decisions matter for the franchise because you'll know they'll backtrack on everything for the next game.