It would be more accurately stated:
I am allowed to remove my headlights, but I'm not allowed to drive on the roads if I have removed my headlights. The restriction is on roads.
I am allowed to remove my headlights, but I'm not allowed to drive on the roads if I have removed my headlights. The restriction is on roads.
I own my home, but I'm not allowed to replace the GFCI outlets in my bathroom with non-GFCI outlets.
Having the right to modify and repair does not mean a carte blanche to ignore and circumvent building and electrical regulations. You do have the right to remove, replace or add additional outlets providing that the regulations are complied with, and you can purchase outlets from any vendor which sells products compliant with the regulations.
Availability of first-party and third-party parts would greatly open up the market for electronic goods of all kinds. So long as they comply with the necessary regulations and perform equivalently to the original parts, it would be a vast improvement upon the current state of affairs.