"Subreddits tend to wildly misrepresent reality due to survivorship bias"

I disagree. If Amazon had great customer service, there wouldn't be a large volume of people complaining.

"In any case, I do wonder if Amazon's treatment of folk like you would improve considerably if Amazon had competitio"

I agree with you here. The only two marketplaces that actually get traffic are Ebay and Amazon. I've tried them all over the years and the rest combined don't even come close.