Some thought experiments:

What do [search engines, social networks, newspapers] look like? I assume they'd all be paid and you'd get some free tastes and then decide which you'd pay for in the long term (à la kagi).

By removing the third party payer, the service provider has no incentive to do anything for them, whether aligned or not with the user. That is the big plus.

What about all the money that companies use to promote their products and services through advertisements and marketing? Some portion of that would probably go to making their products better. The rest... from their standpoint, how do they even get a potential customer to know they exist? That's tough.