That might work well if you're a known author or for buyers willing to spend time digging around but it doesn't help new authors reach a mass market.
Self publishing will have some sort of a positive impact on things but the reality is that large aggregators will still have a very significant role for discovery and in the mass market.
You're right, but my point was that if Amazon became an abusive monopoly, that would spur alternatives.
BTW, I found some of those author self-sell web sites because of Reddit postings about their books. In these days of social media, I don't think the traditional gatekeeper role still applies.
Self publishing will have some sort of a positive impact on things but the reality is that large aggregators will still have a very significant role for discovery and in the mass market.