Fair point. Sybil multisigs. Ideally there’d be an on-chain reputation system with longevity and successful transaction history. But that starts getting fairly complex.
What you’re trying to envision is what the spiderchain is doing. Botanix Labs is building this. Eg decentralized multisigs where >10.000 nodes can participate in.
And pay thousands of dollars for the privilege to run a node. Don't forget that part...
Yes. For txs lightning, self custody or not, is probably still the best option, there is also Liquid and Ark is being developed, so there will be many options and all connected by lightning. Each person can choose the best option, in many countries using something centralized like Strike or cash app for lightning is probably fine, in countries were people can't access these serviced they can use other options, Liquid, Fedimint or a wallet like Phoenix or Zeus as an example.
and Hedgehog! @supertestnet is working on that one