Eternit Cedral Siding Crumbles with too much sun

This is what it looks like after 15 years. It obviously gets worse with every year. What to do? Paint it? that hardly seems an option since the underlying material just crumbles away. The painter also estimated it to cost 3000 euros to paint it.

The other option would be to replace it. That costs 5000 euros. But that also seems like a bad idea if you're going to see deterioration after 10 years.