If you travel down this road you end up with Celestia (with whom I have no affiliation or financial interest). The idea is to support many blockchains on the sa

If you travel down this road you end up with Celestia (with whom I have no affiliation or financial interest). The idea is to support many blockchains on the same data availability layer. There are good reasons for this, but the primary one (as I understand them) is that data availability layers scale well with the number of machines, unlike compute which doesn’t scale at all. Also, it makes it much simpler to have inter-chain trustless clients. Much of the work of writing a blockchain (like writing block explorers, the network stack, etc) can be deduplicated, while still letting you spin up your own low-security chain for a low-security use case.