I definitely agree with the thrust of your point, but there was actually a period of time where none of the fun stuff you listed existed. Email and ftp had to be invented and implemented awhile after the internet was created. There was a period where there was nothing to do on the internet, it just predates most of us. But it was definitely a much shorter period and the killer apps were way more obvious even before they were created. It's still not clear, after all this time, what the killer apps even might be for crypto; it definitely isn't all the echo chamber speculation stuff that is all you can do now ("lend your crypto to other crypto speculators who can't do anything with it besides lending it to yet other speculators!").

Personally, I would like to be able to (legally!) program against my money and do stuff with it without being beholden to big banks. I think it would be cool if I could automatically send 1% or whatever of all my transactions to a charity of my choice, or if I could do my own "micro-finance" lending to farmers in developing countries, or other things like that which currently require a bank to implement it and me to use whatever they implement. But it is far from clear whether all this cryptocurrency and DeFi stuff is either necessary or sufficient to do any of this kind of stuff.