I wouldn’t bother right now.  Yes they have fewer moving parts, but there are so many electronics on board it would make your head spin, in addition to yet unproven battery technology.  And you are dealing with high voltages, so you almost need to be an electrician/technician to work on these.  Also, EVs for the most part are not DIY-friendly especially if you need to get service information for repairs (Tesla does not share anything).  I would hold off for a long time, see where the chips fall (which technology will win out?  EV, plug in, hydrogen fuel cell, solid state, or something completely different?)

Stick to ICE in the meantime if you care about longevity, reliability, still having some control over your vehicle (DIY repairs).  Be sure to pick the right make and model, too, as there are a lot of ICE stinkers out there.

Scotty has talked A LOT about electric car reliability in his videos. Try searching his Youtube channel for keywords like battery, electric, EV, etc.

It’s hard to say because the mass market for EV’s and hydrogen is so new.  I don’t even know if we can call it a mass market yet. 

Obviously, the batteries appear to be first to go. Just from anecdotal evidence.

We can conjecture a little bit about Toyota hydrogen cars. Talking with some Toyota engineers, it seem their electric components for hydrogen share much with the electric components of their hybrids.

And we know their hybrids also last a long time (the battery surprising seems to last at least 10 years, my Prius battery lasted 16 years.)

But really, it s anyone guess.