it's literally what blockstream liquid does. even lightning does this. it's bitcoins locked in a HTLC where they get unlocked on some other accounting system somewhere else. sometimes there is a decentralized two way peg like in the case of threshold tbtc or even lightning, and sometimes there actually isn't like in the case of blockstream liquid. people spent a lot of time talking about decentralized two way pegs. this whole thing is enabled by segwit, which made HTLCs possible in the first place. I guess you were not paying attention, all you focus on is lightning, and there are no other scaling solutions. I get the feeling that you have never actually studied any of these moving parts.