Nah, you're missing an _extremely_ important factor: people who are enthusiastic about data applications can just run archival nodes. Doesn't take very many of them for it to work. And unlike other protocols the default is for a whole lot of people to do exactly that, because the amount of data used by an archival node really isn't all that much.

Bitcoin from that perspective is basically a battle tested DoS hardened data archiving protocol, with a bunch of software already written to implement it all.