As a small business owner (blacksmithing), I fully support this. However, about 85% of our business is through an Etsy storefront, about 10% through Amazon, with the remainder through our own site.
Haven't focused on reenactors specifically. Most of our stuff is home furnishings. Hooks, plant hangers, curtain rods, pot rack bars, drawer pulls, joint braces for woodworking, fireplace hardware, decorative chains (like for chandeliers), etc.
Great point. The limited times I have purchased from Amazon in recent history was accidentally in this manner. I think that purchasing directly from the creator's/company's website might send a message that some folks would like an alternative, but I don't know that. Either way, it is less amazon.
Many small creators also sell directly on social media. Unfortunately that's mostly corporate owned social media, but at least they dont typically get a cut of the sale.
Even still, local creators will often pop up at events and conventions and stuff. They may not have a permanent presence, but you can still often buy stuff from them in person if you keep up with where they'll be.
Buying a domain and a webhost costs money and people would need a regular income for that
What I'd like to see is some co-op online platform where people can collectively contribute to online costs though a small percentage of fees and / or donations