... Sheet music is optimised for people. Piano roll is optimised for computers. If you're interested in getting as much detail as humanly possible across in a parseable manner to another person, then sheet music doesn't even have competition - over the centuries people have worked out what is important to get across and sheet music is an absurdly efficient way of communicating these most important elements to a human player. The other benefit of a human player is that they will fill in blanks for you - a violinist doesn't need to have the precise velocities of every note indicated in a crescendo, they just need a start and an end. A trombonist does not need the precise pitch bend at every possible timestamp recorded, they just need a wiggly line or a curve. This symbiosis between sheet music instruction and player response is what makes sheet music the undeniable front runner for human performance. Never a day goes past where I don't remark on the absolute miracle that is sheet music.
If you want to have a computer respond with the exact instructions for each and every note, then piano roll is the only sensible choice - linking visual presentation with how the data is actually read and played back by the computer. It would be silly to try and cram that all onto sheet music, and even if you did, no human would be able to take in and respond to every little instruction for every note. Piano roll only makes sense for computer usage, and the only sensible choice for computer usage is piano roll. It makes sense for you, the composer, to have full access to exactly what the computer is working with and will be doing, rather than guessing and hoping the notation parsing is up to snuff.
There is a place for both in the world, and they are both extraordinarily powerful tools in their own world's which don't quite work when filling the role of the other.
A lovely comparison from Reddit.