Allowing advertising quickly makes everything about getting more eyeballs and therefore more income from advertising. Users aren't the customer, they are the product.

That directly leads to all these addictive dark patterns.

All human laws are arbitrary in the sense that they have no natural precedents. We made them up because they make society better when we have them. Sometimes they end up not doing that so we change them as needed. In this case, a lot of people think society would be improved if we created this one.

Endless, near inescapable psychological manipulation. It has crept up slowly, and some of us have been feeling the negative effects longer than others, but it is so so so much worse than it was even 10 years ago.

> What harm is being prevented by banning advertising, in general?

The harms of addictive design in internet social media.

Regardless, my point was just to answer the question, "is it okay as a business model?" Ostensibly, if advertising online were banned, a business model centered around selling online advertisement attention would not be ok.

Theft of attention. Your attention shouldn't be the website you visits to sell.