Transaction fee and confirmation time highly depends on the network traffic so it will be eventually high if more transactions are made at the same time but no one ever said bitcoin is the only crypto suitable for payment, there are lot other cryptos as well so we can choose cryptos depends on the value of transaction but the real thing is people are ready to accept decentralized mode payment system.
I am not sure it will be easily accepted by people all over the world. the problem is not only in transaction costs, but transaction speed as well.
at this time perhaps almost all countries also have platforms for payment in exchange for fiat money which we must carry on. like a digital wallet that we can use to pay for transactions. the question is whether the bitcoin or crypto function that will be used as payment can replace it even better than the platform that already exists and is used on the market?