We will eventually have a trustless way to share UTXOs and Liquid or Fedimints or Arks (or whatever comes next to improve upon them) will be the way most people interact. Lightning is also likely to be more for settlement between institutions. More horizontal scaling may come in the form of cross input signature aggregation or something like that. Increasing the blocksize doesn't solve the problem. It's only a linear improvement in capacity & it is a compounding increase in the cost of node operation. You cannot sacrifice network infrastructure to gain functionality.