The largest constraint on this (in the context of the FIRST competition) is that community matters at least as much as technology.

If you're using Java (or C++ or LabVIEW, to a lesser extent), you at least have a hope of posting to a forum and going "Hey, we think our robot should be doing X and it's doing Y, here's our code, any insights?"

If you use <bespoke language X> and your own custom bindings, you're on your own.

We can use whatever software we want as long as we use the specified hardware (the NI roboRIO), FIRST's latest firmware, and comply with the match system and safety systems that enable and disable the bot at different times. Many teams have been using a community Python alternative called RobotPy for a long time despite it not being officially supported and FIRST had no problem with it.