I think you are missing how much D&D abstracts combat already. It's not worth trying to add that granularity to combat in D&D. If it's something you and your friends enjoy then have fun with it. It's not something everyone is going to enjoy. Nor is it any more sensible than how D&D already handles it because combat is meant to be an abstractions. You aren't standing around for 6 seconds. You are dodging, parrying, moving and in general fighting the whole time not just when you attack. An attack generally represents an opportunity to break through the opponents defenses. Since D&D isn't trying to model the whole combat sequence but instead abstract a good chunk of it out I'd say they decided there wasn't enough difference in most martial weapons effectiveness to warrant changing mechanics for each one.
Maybe abstractions are something you have a problem with?
The reason a greatsword deals more damage than a dagger, the reason a longbow can make ranged attacks, the reason a fireball deals fire damage, is because that's how those things would work in our world. DnD could have abstracted away everything and just made every weapon work exactly the same, and I would argue it would be a worse game if they did.
But the point of these fighting styles wasn't just to make the weapons feel more distinct, the point was to provide players with more options in how they actually fought. Right now there are very few options for fighting styles (when you remove the fighting styles your character can't benefit from because of their choice of weapon, there are only 2, or 3 for characters with shields), and none of them are that interesting. That's what I was trying to fix.