"thats how we did it before" is the number one inhibitor in the name of progress.
Remember your windows pre updates. Full of security holes and no way to patch, or bugs that linger and create problems that could never be fully eliminated.
Let me tell you something you didnt think of. Imagine i am doing my diligence before releasing a software but didnt fully factor in all the unknowns in the process. It happens, shit breaks all the time, right? Now imagine instead of uncontrollably calling everyone in house, i start 1% roll out, and gather data, find some problems with that investigate and push the real fix. See the efficiency gains? I prevented the chaos of 99% of cars, and i did somrthing data driven
Good luck on that without an ota.