>BSV seemed to scale just fine, and you could also store entire files on it, including JSON, HTML or even music or videos

This doesn't pass the sniff test. Everyone must store the full blockchain in order to verify it. So to run a full node you would have to store everyone's JSON, HTML, music, videos. Full mirroring for every node in a distributed system is about as close as you can get to the definition of doesn't scale.

I should note, the scaling I was referring to was transaction processing. Data storage is a little different.

The architecture which I heard described or hypothesized was more akin to Amazon deep storage. More frequently accessed data would be more accessible on "hot" nodes.

Full nodes would effectively, under this paradigm, become cloud storage providers. As a bonus, the problem of how to charge for access is basically already solved, and does not require a complex corporate payment scheme.

Indeed. Bitcoin's blockchain grows with a laughable 3kB/s, yet is an unwieldy 700 GB.

A blockchain that allowed you store one song per second would be hundreds of TB before long. There are other architectures for that sort of thing for a reason.