Imagine if you could take an old Android phone, install a Nextcloud app, do a quick OAuth2 flow to set up a tunnel, and now you have 100GB of cloud storage, sync, calendar, etc all running from a desk drawer.
Port forwarding is too hard. DNS is too hard. IPv6 is going to take another 10-100 years and people will still have to figure out how to manage firewalls.
IMO web3 is going to come by lowering the barrier of entry to self-hosting.
I am hesitant to commit to a tunnel-based approach because where I live I get frequent power/internet outages. I feel that tunneling is something I would explore if my application grows to the point where I would need to rent space in a colocation.
I don't think tunneling is necessarily a great for hosting large-scale things or businesses that need to stay online 24/7. Self-hosted services for friends and family or maybe small communities seems like the best use case.
It's annoying but ok if your media server goes down once in a while.