Because I can't find 1 main reason to choose Alby instead of a custodial.

If I am scared about getting rekt from a custodian I just won't put more than 50/100k sats in there at a time.

A normie user, has no incentive or benefit paying 50k sats just to setup a channel, and testing being sovereign, with possibility to find more problems than advantages from that configuration.

Don't get me wrong, for a bitcoiner with big stack that has years of experience, maybe good, but maybe he does use it with his own node and everything else, so.. you are looking to onboard the 100Milions or more users? Not the way IMHO.