As a touchscreen laptop user, I find it a shame that there is no java alternative for this

There is this mod, but it is old, for forge, and in 1.12.2
https://github.com/Aang23/MC-TouchControls

This mod had touchscreen stuff a long while ago, but it ended up not being possible at all due to the terrible touchscreen capability of desktop operating systems.

If I remember correctly, I technically haven't removed the code for it, it's just inaccessible.

The issue that I encountered with touchscreen is, well, on desktop it considers it a single pointer: the mouse, so you can't use multiple fingers at once, or you would need to access some very low-level, potentially breaking libraries to hack into the system to just make it work.
So yeah, not worth it imo.

I just read the readme, and I have the impression that it is not up to date