Great, you have a simple rule that's wholely unrealistic and as poorly construed as pretty much everything else you've been saying so far. Such a rule could so easily be worked around that it may as well already exist for all that it would matter.

I'll again reiterate that I agree with what you want to argue. I agree that I think Steam could probably take a smaller cut, still be profitable enough to stay in business at the same scale they are, afford more smaller businesses a better cut of the money they're generating for themselves and for steam, and give the option to charge less to consumers. I agree that there are too many mega corporations, making way too much money, screwing too many of their clients, customers, and employees. I agree that too many executives are making genuinely fuck loads of money that are inhumanly excessive.

I'll still say again though, that pretty much everything you've argued so far is wildly unrealistic, unfounded in reality, barely thought through at all, and comes across as the absurd ramblings of a middle schooler who passed an economics elective.

I'll also point out the hypocrisy of you attacking Steam (and to your credit other distributors retail or otherwise) but defending the publishers that by your arguments simply must charge more or else they don't make money back on their investment. Your argument defends AAA publishers such as EA churning out games year after year with the exact same code just different stats for sports games (FIFA, NBA, whatever the current football games are), games exploiting gambling addictions (pay to win, FOMO, loot boxes), and games exploiting the efforts and attention of children (Roblox).

Also "something must be broken in your brain for you to defend them instead of your own interests" is rich coming from the person who's very visibly experiencing double-think seemingly genuinely arguing "of course publishers aren't going to charge less for their titles on other digital marketplaces because if they need a $49 RoI on Steam then they're going to charge the same $70 price on other platforms" at the same time as "well if Steam didn't charge a 30% cut then you would pay $50 for an otherwise $70 title!" as if you don't believe in your own argument that they would charge the same exact price on Steam as they do elsewhere.