If you built your own shopping mall, you could decide whether or not to allow a Hooters on the property. This seems pretty fair to me.
I am directly stating this is a problem; I don't really think I understand your rebuttal. I agree such a platform assumes a massive amount of control over your business, but I find it highly disagreeable both that this is the way platforms behave, and that this is legally permissible.
Indeed, your analogy is as if the "mall" would allow Hooters on the property for 5 years, and then without recourse to the resident Hooters be allowed to nullify their lease & expunge their business overnight, without an authority to speak to nor legal protections against this eviction, which predictably was the entire lifeblood of the franchise as this "mall" was offering interesting web tricks like "available all over the globe with no need for redundancy".
Seems like a big problem no? By moving to the web, platforms assume even more control with far less regulation over your business than your landlord ever could dream of. Yikes.
We even use our own Payment processor!
Be careful with Shopify, they will pull the rug out from under you and there is nothing that can be done. I don't recommend building a platform on top of this.