Though it's just our hope. Here are some calculations that show there is only a 21 million fixed supply of bitcoin but the world is still not adopting bitcoin entirely. But when people start recognising it, they adopt it and invest in it.
rationally.. at code and hard data level.. there will not be "21million bitcoin". because at code/data level. the units of measure are actually satoshi's. by which there are going to be 2,099,999,997,690,000 sharable units.
which if we trim off say '2million btc' lost is
1,899,999,997,690,000 sharable units
which if just say 5% of the planet wanted to invest in bitcoin means if equally shared. that
of the 5% of the world that may want bitcoin they would need to fight over 400,000,000 equal shares of 474,9999sats.. or 0.0475btc
so if each person was to say invest just $5k in btc. for an equal share of btc..
that 0.0475btc rationally would be worth $5k.. which would rationally. be 1btc=over $100k