How do hosts of those instances afford to make them free?

Why would that be the case in the future? It was in the past, when people used to maintain whatever they made/bought and use it until it was completely unusable, because they were too poor to buy a new one

Industry and automation made production way more cost efficient, but didn't do the same for repairing, probably because it's not as predictable and automatable as making stuff from scratch

You can repair a lot of stuff, but you usually have to pay more than the price of buying a new item

Or made it easier, since you could do maintenance on the panels with some rail cart directly. I see how solar roadways may not have been convenient, but with rail it's not as dumb. Placing the panels on the side also means more land use, and not every place in the world is spacious, especially Switzerland

It may become cheaper once they cut all the various safety and environmental regulations