Minecarts could be greatly improved if they were more robust. Currently, they are the most expensive (and time-consuming to build) transportation method, but have a number of issues:
- A mob that gets onto the tracks will completely clog up the railway until you remove it (or it walks off). Mob AI avoiding rails doesn't work 100% of the time, and having to build fences around your railway adds to the already expensive cost.
- There isn't a reliable way to link minecarts together. You have to deal with finicky methods of having Furnace Minecarts either push or pull other minecarts, both of which tend to come undone after a turn or elevation change.
- Minecarts are slower than almost any other form of transportation, besides walking and llama caravans.
So here are some ways I think they can be improved:
- When a minecart runs into a mob, it pushes (or knocks) the mob off of the track with a minimal speed loss.
- Furnace minecarts are obsolete due to powered rails, so instead they should simply act like normal furnaces that smelt things with a GUI. Would be useful for long mining trips.
- You should be able to properly "chain" minecarts using leads to form actual trains. The minecart at the front would control the acceleration of the entire train (in terms of slopes/powered rails).
- Minecarts should have a solid hitbox that blocks movement, like boats. This may also fix weird bugs of minecarts stacking or passing through each other.
- Minecart top speed should be faster on straight tracks, to make it competitive with other forms of transportation. Going around sharp (90 degree) curves could cause a large speed penalty.
TL;DR: If nothing else, Minecarts should at least push mobs off of the tracks instead of being blocked by them.