> If shopify is not holding up its end, there are already legal avenues to compel them.

The issue is that you can't use the standard, low cost venue for small b2b disputes (this one was over $7,000): the local small claims court. Most contracts will stipulate a convenient venue to the author of the contract (which may cost more than $7k to litigate if you are out of town). Federal court requires a bigger injury and won't hear your case. In many jurisdictions, business cannot self-represent in small claims, so even if it is available, it's expensive. You end up hiring outside counsel, even if you have lawyers as employees which raises costs a lot, and opens up the possibility of a suit where the awarded legal fees dwarf the amount in dispute.

don't most of these sites, like Shopify, require arbitration for disputes?

or do you worry about actually enforcing an arbitration decision?

Enforcing arbitration is usually pretty easy - most of the time the company will honor the decision. It's when they don't that is the problem, or where the situation is not a contractual dispute that can be arbitrated.

> I assume there are contracts involved. If shopify is not holding up its end, there are already legal avenues to compel them.

The answer to consistent bad behavior can't be "well, just sue!" because the US court systems are already underfunded and jam packed as is. It just doesn't work to (only) have breach of contract lawsuits in David v. Goliath (202X) suits.

If a platform is big enough, it will write one-sided contracts permitting their abuse.