> But today, many sellers hand close to half of every sale to Amazon. Half!

This is how resellers work.

Back in the 80s, I was selling my compiler direct. I also engaged a reseller, if you recall, those were ones that advertised in computer magazines with full page ads crammed with items for sale.

The resellers demanded that I sell it to them at half the retail price. I was shocked and horrified! I soon found out, however, that all resellers are like that. They cannot make money otherwise.

Amazon is no different.