Make Players Rideable with /ride

(Java) The /ride command is great, but it could be better. Players cannot currently be ridden by any entity, including other players.

Allowing entities to ride the player can open up a lot of opportunities, from easily having players ride each other, to having display entities ride players, so for instance players can look like they have a block above their head.

But the best reason is for mapmakers trying to transform the player character. The best way to replace the player body or add attributes such as a sword on the back or wings is by teleporting the entity to the player position, but that looks jittery and not convincing at all.
Unlocking players to be rideable opens up a world of opportunities for creative people in the Minecraft datapacking space.

(ps. I reckon this would be a common suggestion, but haven't found any similar posts)