I’m torn on variations honestly. There are characters where I think it’s awesome and then a lot of characters where it highlights how bad the system is.
For characters like Reptile, Takeda, Cassie Cage, or Ermac who have a very solid variationless moveset, they can add variety in variations and the system adds a lot of fun and depth to those characters.
On the flip side you have characters like Sub-Zero, Predator, Triborg, Erron Black, and Ferra/Torr who all have a variation with really strong tools (tools that come from the variation, not the base character), so because of this, the base character has to be dumbed down to compensate so the character feels incomplete at times.
I’m not saying a Sub-Zero type character is necessarily worse than a Reptile type, just more polarizing, less fun, and more imbalanced.