nostr:npub1p34kn5su0fzjmsqx7wegqftnd34xr7as808udkxyltcl9zw6jrqqajwdy6

Because once the coverage starts to approach a whole niche you have complete control.

Imagine the extreme of either of these cases, where the vast majority of people and companies decide to collaborate. Price fixing allows you to set unfair prices that prevent competition from undercutting you as you can fix the price locally to beat your competition while raising the price marginally everywhere else to make up your costs. Then when your competition goes out of business you just bring prices higher int he area and recoup your costs again.

It completely prevents competition from arising and thus eliminates any possibility of a free market.

nostr:npub1ukcz3c3ek9ugnmrj37cjm2q9gsaqss5j9dqwpqmx0tgkzudsseqqcp40jn