YouTube and Netflix cache boxes are important for smaller ISP's. Their cache performance can literally make or break the monthly P&L. That said, I haven't heard about other OTT services offering a caching appliance. And there are more and more OTT streaming services coming. It's great from a consumer perspective, but it's going to be challenging for smaller players.

Moving towards decentralised internet infrastructure such as https://ipfs.io could help with this. ISPs setting up IPFS caches for their customers could save a LOT of peering bandwidth.

Solution is to get some datacenters on your network as well. I'm not sure why that didn't happen before.

How would a rural WISP "get some datacenters" on its network? Sorry, I'm not grasping your previous comment.

If you have the problem that peering is getting very one-sided, the solution is to get the other side as well. So a rural ISP should try to expand into an area with cheap power and offer low-cost hosting and bandwidth to attract servers.

This is downright silly. The bulk of bandwidth is associated with a select few destinations that aren't going to put their datacenters behind a consumer isp under any circumstances. But many do offer caching options that allow content to be sourced inside the ISP.

Hard to do that when everyone runs everything in the cloud. That's a very tough market to crack into.