My argument is that the maintenance overhead of a finished product (or car, or building) should require much less effort than what it takes to build it - otherwise you should seek a refund from the original manufacturer(s).

That's absolutely not true in pretty much any mid scale software. You can have a team of 5 people make the core of an app, then need 50 people to help with support for customers. scaling up is never cheap, but software scalability is really low despite that.

That's not even true with a car. I'm about to spend 3000 dollars on a big repair for a car I bought 9 years ago used @ 3500. Even if you adjust for inflation we're still talking about 70% of the car's worth just to keep it running. As for a refund, the blue book value tops at 850 dollars.