I have a vague understanding of how lightning works with opening channels etc...

The only way I can see a crypto payment system receiving mass adoption is if it can be used exactly as current payment systems are used with the end user not seeing a difference. It doesn't sound to me like this is possible with lightning.

There are 3 things that need to happen IMO:

1. An end user will need to be able to transfer BTC to a wallet on a phone and then just use that money across multiple retailers without having to think about it? Paying using NFC or QR codes.

2. Retailers will need to be the ones paying the fees, as they currently do with payment systems. End users don't like paying fees and they are more likely to use fiat as they see a feeless option.

3. It needs to be possible for the user to pay while their device is offline.

Are these 3 things going to be possible with lightning? My understanding is that they won't be and therefore IMO lightning is not the answer.