The point of this "habit" is simply to not create onchain dust. So if you have a channel opened with the change of like 50-100k, that's not going to get you very far. We're kinda seeing with high onchain fees that channels need to be big or bad things happen.

But if someone didn't have any LN channels they could receive a LN payment to custodial wallets like coinos.io or wallet of satoshi.