Now, you're 100% right about discoverability. But Amazon is misplaying here if that's the long game. They should be a quality filter, not a cheap marketplace of knock-off Harry Potter toys.
You're also right that Google isn't nailing it. Really, I would argue that tastemakers are still leading the way for physical goods; with rating systems coming in a distant second. Ultimately I think a web of trust is going to develop to solve many of these problems, but that is largely a task of user interface, since enumerating trust and context is too onerous to push on a user. Besides, making it explicit is provably gamed as much as possible, see LinkedIn's "skills" for example.
Or Google could get its act in gear and cut amazon out of it. Hard to tell what will happen.
The manufacturer cannot easily sell to end users, as it requires fine tuned delivery platforms and most of all, discoverability. SEO alone is not enough for a manufacturer to get noticed, so Amazon will benefit from being the de facto “search” for products. Anecdotally I and most of my friends and family already do this. It’s rare that I have intention to purchase <sub big ticket item> and google it.
As for Tesla, yeah I think it’s time to bet against him. There were many many “great men” like Musk in the 80’s and 90’s that made 1 too many misssteps and ruined their companies. Elon is on a razor’s edge.