Agreed.

One thing they could do is replace the gold cost of powered rail with copper, to continue playing in to that utility, and then add a different kind of rail using gold which is capable of greater speeds (maybe not quite boat on blue ice speeds but something close).

Maybe add “stop/go” rails that don’t require redstone to function, only player input. Can set up a station that stops a cart when you arrive, and then allows it to boost off at higher speed with a single keypress when you get in.

Let people chain minecarts together to travel with other players or to carry multiple chests worth of items out of a mine.

Knowing Mojang’s speed of development, they can maybe do one of these things with a lead time of 2 years.