Thank you, that's a good argument. Two further points though :
I was addressing the question regarding why an alternative banks is appealing. This is the motivation : we don't want to be screwed and have lost the trust we once had in various financial organisations as we perceive them to have moved from offering a service to holding us to ransom. There isn't necessarily a good alternative available but we wish there were, so we are attracted by schemes that claim to offer that. Marketing people also know this.
I agree that monitoring to ensure safe transactions is mostly inevitable. But it could, as it once did, go no further. There isn't any need for it to feed into advertising or governmental control. Bitcoin (whatever the failings - I'm talking about appeal here, not practicality) promised this by using maths to do the policing rather than corruptable organisations.
Ultimately, that will probably be the requirement : Governments or corporations holding the security and maths verifying the transactions. Because no organisation holds sufficient trust any more (Facebook is only the worst option, the others aren't a lot better) and will not again - it is often said that trust, once lost, is harder to regain.
But we're not there yet in capability (see argument elsewhere about power consumption, and the known security problems of exchanges), and those organisations will fight hard to keep control of the transactions. So we're still due a very long period of the existing state whereby we use competing organisations to keep the others 'honest' (fvsvo 'honest').