Can't you open a normal online store that doesn't rely on Amazon? You could try shopify, or etsy, or sell on eBay? Or make your own?
Otherwise I feel it's a chicken and egg. It's like saying we need Amazon or a similar big known marketplace so that customers can find you and buy from you, but at the same time, we don't like the concentration of power it brings.
So if nobody tries to open an online store on their own anymore, what then?