I can imagine a future in which for LN users don't open their own channels at all: you just buy LN balance at an exchange, the exchange opens large channels, and you use their channels for buying coffee.
I know some people won't like that level of centralization, and I'm not a huge fan of it myself, but if that's what it takes to reach mass adoption, I can live with it. And if you really want, you can always pay the additional on-chain fees to connect your own node.
If you are buying a LN 'balance you are buying a database entry. If the exchange has many customers and merchants, there would be no reason to use LN, you could simply pay another exchange customer, and the database could be updated.
I wouldn't like the scenario in which everyone relies on the same exchange. If there are (say) 20 large parties offering LN, 95% of my transactions would be to users who use a different exchange. It may be just a database entry at the exchange I'm using, but they'll need to make an actual LN-transaction to the other party when I make the payment.
does already.