[altantiprocrast]

I can only speak for Vex V5 (one of the systems they teach) and VRC, but from a competition and user standpoint:

Scratch is used when coding isn't a focus, and mechanical engineering students just want to 'get the job done'.

C++ is used because it's probably the most 'pro' language. Close to bare metal unlike Python, but object oriented and stuff unlike C. C++ is used pretty much any time complex algorithms, threading, etc. are involved during competition.

Recently Vex has been trialing Python in Vexcode, but it's relatively new so they might not have built courses for it yet, if the even plan to.