Custodial lightning versus custodial e-cash, there's no real difference. However, it's getting hard to get a custodial lightning wallet that doesn't require kyc. That's the benefit of e-cash. Basically, lightning without kyc.

There is a setup cost with non-custodial lightning. So, for some people, especially first timers, a custodial wallet is at least a start. Something they can use until they can afford to fund their own lightning channels. So, for a non kyc lightning wallet, pretty much e-cash might be the only option for now.