If you can't be self-custodial on L1 you can't be self-custodial on L2

If you could be self-custodial on L2 without L1, it would become your L1 and the original L1 would not be needed.

Using one L1 tx to get 100 L2 tx (if you somehow manage to balance it that way) means you have to freeze capital for at least 100 tx in front. How many people are liquid like that and can actually do that?

The whole scaling through layers is a red herring. There is no substitute for L1 scaling.