KI and SFV have entirely different reasons as to why the games are the way they are.
SFV follows an early access model but charges a AAA price tag, which is no doubt very confusing to the casual fans that picked it up expecting it to be like every other previous SF title they'd bought in the past.
KI followed the early access model but understood that, so they only charged you £15 for the Combo Breaker pack, which was everything you could have needed to play the game to its fullest, then KI Season 2 comes out following the same business model, but once again charged us another £15 for the full pack of S2 characters and the modes that came with it. For Season 1 and 2 for KI you paid £20 less than what you paid for SFV.
KI's price tag made sense, SFV's does not.
Let's not forget that both games have Microtransactions too, I've always found Free to play shenanigans in a full retail priced game to be extremely annoying.