Yet again, I see dissident right wing people on X are surprised when a Big Tech cancels someone off their service for political reasons.
Shopify had yeeted alt right people off before, notably cancelling merch stores after the Charlottesville riot in 2017.
DO NOT USE THEM, they are off limits to you. Yes, that means you will have to put some effort into your merch store. BOO HOO. Nothing resilient is ever easy.
I agree, building a reasonably useful storefront from scratch would take a couple engineers a couple months, and that's assuming you use a payment processor like Stripe. Even when using spotify, Kanye made a custom UX which probably cost a non-trivial amount.