You can still very easily buy a PC which has an "open" architecture in the sense that you can plug various CPUs, PCIe cards, memory, disks, etc into it. It's in a very similar form factor to the old "open" PCs, it sits on/under your desk in a sheet metal box. That hasn't gone away, we just now also have these new things which are tiny very portable computers which are locked down and very closed.
I expect EVs which sell well will have robust 3rd party parts available for the kinds of parts that >95% of owners will ever need to replace, just like today. The EV industry is still extremely young, there will be much money to be made with 3rd party parts and repairs on EVs even if the automakers don't want it to be. I firmly believe that the market will find a way for the popular models.
> we just now also have these new things which are tiny very portable computers which are locked down and very closed
...and that need replacing every couple years not because they don't work but because we have been disallowed from replacing parts, thus generating e-waste made up of rare earths and toxic metals and at great cost to people.
I expect EVs which sell well will have robust 3rd party parts available for the kinds of parts that >95% of owners will ever need to replace, just like today. The EV industry is still extremely young, there will be much money to be made with 3rd party parts and repairs on EVs even if the automakers don't want it to be. I firmly believe that the market will find a way for the popular models.