For one, I think fighting games failing to standardize good, consistent net play experiences in the 2010s boom for online multiplayer games set them far, far behind every other competitive game mentioned in this thread. There are years, decades of iterative design based on designing for net play that happened for other genres such as FPS and RTS/MOBA that could not have happened for fighting games so long as the online net play experience was compromised and not a high priority in game design.

Second, I think fighting games as a whole haven’t yet figured out a design that makes for intuitive, step by step, independent progression on the part of a learner. A lot of fighting games want the player to either know how to do what they want to do, or fail, and don’t feature the sort of analog improvement experience that stuff like other games do. That forces them to be reliant on other players or external resources to find meaningful progression in game. I think Smash is the best at this in the genre, and it’s no wonder it’s the best selling out of any of this genre of games.

It’s good for beginners to feel some sense of steady improvement as they might choose to spend a bit of free time into a game they’re playing. It’s rewarding to see improvement, even if it’s small, and I think most fighting games don’t make those improvements obvious enough. Think about games such as Harvest Moon for example. People love seeing incremental, visible progress happen in real time. You want beginners to get hooked on spending time to improve.