1 sat will reach parity with 1 ct at 1 Mio. $ / 1 #BTC.

That implies ~20 trillion $ market cap for BTC.

That is ~twice that of gold today.

If bitcoin is to become the universal reserve asset or global currency it seems we need finer “resolution” than one sat.

What would such a change imply? Hard fork?

E.g. it seems miner subsidies could be paid for longer since more halvings would be possible. However the 21 Mio. Cap should not be breached since it is anyway an asymptote.