I agree though, my dream for years has been an open source CubeSat bus design that covers say 80% of academic CubeSat use cases and can be modified by the user for the other 20%. Unfortunately I have very little free time these days with family commitments.
And ... professors love making students reinvent the wheel
One should limit the number of wheels being reinvented each time, though. What would also reduce the time-to-space of those projects. The design should cover 100% of the CubeSat, so the students can redesign any part they want.
Surely this, or something like it, exists?
Imaging a group building an managing a robust power supply design for Cubesats that can be immediately ordered from JLCPCB. With a well maintain BOM list.