What really goes on during a BITCOIN Hash is it a Collective Supercomputer Network?

What really goes on during a BITCOIN Hash is it a Supercomputer Network?

So I know the theory on bitcoin mining "work" that takes place and how that work facilitates the network and transactions, but the sheer amount of volume of data to be processed and "mined" is not reflective of any other similar crypto that is capable of doing these transactions in seconds.

My question is what is really going on during this hash work?

I recall many years ago that S.E.T.I. was a Screensaver that would do similar work and run computations for the Search for Extra Terrestrials. Basically turning idle computers into a networked supercomputer.

My theory is that Bitcoin mining is doing that exact same thing with data cloaked within the algorithms and packets. If my theory is correct... who's data is it and for what purpose? NSA, CIA, Russia, China? Another entity possibly.

Think about all of the Bitcoin Miners out there contributing to this network, the data processing capability is massive. This supercomputer network is made possible by the cloaked data under the guise of a crypto system that offered some form of payment. If my theory is correct, kudos to the developers but masking this is dirty and likely malicious!