That depends on how old and big is the project. For example Linux is "stuck" on GPL2 and even if they wanted to move to something else it wouldn't be feasible to get permission from all the people involved. Some contributors passed away making it even more difficult.

How is the problem of "you signed a CLA without authorization by your employer to do so" solved? I'm mostly asking because I saw the following:

"I will not expose people taping out Hazard3 to the possibility of your employer chasing you for your contribution by harassing them legally. A contribution agreement does not solve this, because you may sign it without the legal capability to do so (...)"

https://github.com/Wren6991/Hazard3/blob/stable/Contributing... (this is I believe the repo with design for riscv cores running on RPi Pico 2)

These are the ones I refuse to contribute to.