Max supply is irrelevant at best and detrimental to BTC being money at worst. Due to the perceived opportunity cost of spending Bitcoin now and losing out on future gains, bitcoiners choose to not spend Bitcoin undermining it's purpose as money. This oppoetunity cost of spending Bitcoin is going to increasingly become a problem as mining becomes less and less teneboe for miners. Monero's slight tail emission and uncapped supply make it sound money with a velocity of money in which people still choose to spend in commerce unlike with BTC. It is actually used as a currency due to the fact that the perceived opportunity cost of spending monero doesn't incentivize incessant hoarding like with BTC. Monero is just designed to be better money.
Discussion
That is a fallacy. When Bitcoin is fully monetized it will just go up at the rate of technological progression passing down cost savings to everyone equally. That's what money has to be able to do first before or can even begin to dream of people holding it so they can exchange it for other things in the future.