I think ecash is probably the best scaling solution we have for bitcoin as it currently stands. While there are some interesting solutions being proposed, most if not all of these other solutions require a dramatic hard fork to the bitcoin network that I dont think are worth the risk.
I know cashu has been a hit, but I think fedimints are going to win out in the end. Its easier to place trust in an organization that in a single person. Especially if it goes the intended route of fedi where families and small communities run the fedimints. This plus bitchat could bring bitcoin finance mainstream.