That is correct, ecash only makes sense if there is no need for identity.
IMO, this is a whole new (old) way of doing things. It is shifting the data balance back to the users. I think of this as a solution for companies and customers that want to opt out of the data collection business model and just go back to the "I sell this, you pay for this" model.
I think this can be used in any industry, it just depends on what the providers and consumers value.
Me personally, i dislike everything that requires a signup/email just for the purpose of advertising/selling me more stuff, and i would hope other customers feel the same way and force the market in that way.
But maybe it's just me, in which case this will remain niche