I think if all the paying terminals will accept bitcoin and google pay / apple pay will integrate the lightning wallet option

So simply top up your sats balance and then use it as you use apple pay / google pay wallet

In this case there will be no UI change for normies and they will just use bitcoin as money

P.s If by adoption you meant usage, in your example the no capital gains thing will catapult the bitcoin price in fiat, but not the actual usage adoption