Most of the points raised here are better suited to the ‘ecosystem’ section than to the technical discussion section of the forum.
Please forgive me for being blunt, but I do think that this approach is fundamentally mistaken in the sense that it doesn’t recognize the primary product of Polkadot, why that product is useful, whether that product is easily replicated, and what users it might find.
The primary product of Polkadot, as with other blockchains, is blockspace. The blockspace produced by Polkadot is of high quality, with high security guarantees, and highly flexible. In the marketplace, that’s a product which will be of use to many products higher up the value chain which neither use DOT exclusively nor avoid self-governance. This blockspace is a commodity. The mechanism of allocating blockspace via parachain auctions is only a detail; a packaging of the product for the market and the mechanism’s existence is only proof of the fact that Polkadot does not produce infinite quantities of secure blockspace from a finite amount of capital at stake and finite amounts of underlying compute & networking resources, which I personally don’t find either alarming or contentious.
The key question for any alternative relay-chain or indeed any alternative blockchain is whether it can gather a significant level of economic security to produce blockspace which is attractive to the market. The rest is just a question of administration & packaging of blockspace.
I would strongly contend that Polkadot itself is not a chokepoint but that it is rather the acquisition of economic security (i.e. capital at stake) which is a chokepoint. Creating more relay chains (or free-standing blockchains in general) means higher competition for the scarce resource of capital, not lower, as compared to the approach of leveraging capital at stake into larger quantities of secure blockspace altogether.