some devs have proposed this many many many times.
simply changing the cap from 21mill to a bigger number can be done but a majority of nodes need to accept this new rule.

in actual fact there are 2.1 quadrillion shareable units of measure (called satoshi's) right now
21000000.00000000 bitcoin
2,100,000,000,000,000 satoshi's

some people have tried also to pretend to keep the 100million satoshi basket term of bitcoin at 21mill baskets.. but allow more units of measure/shareable units(sats/millisats) per basket(bitcoin)

this is where bips about allowing millisats have been proposed. but the end result is the same
increasing the shareable units of measure above 2.1quadrillion, either by allowing more baskets(bitcoin) above 21mill or allowing more units per basket(millisats) both RUIN the rarity value of the currency.

its like gold.. if its known that there are only about 200 tonnes of gold with 170t mined so far and someone comes along and says they can make a million tonnes in a laboratory.. the gold market will plunge..... answering your question. it would be lower

just be happy that there are 2.1quadrillion shareable units

Why bother increasing the max supply when idiots are doing hardforks.

In theory it's software, anything can be done. in practice increasing supply would without any doubt result in a contentious fork as there are a very strong Group of us users that do not even remotely consider accepting such a change.

The change you "might" see if bitcoin were ever to reach truly insane values (say 1USD per satoshi) would be a further subdivision of the currency (i.e. adding 0s after the decimal place).

So the most sensible answer is that it's impossible to increase the supply, because even if the entire dev team chose to and realeased versions to this effect, a large portion of the community would refuse to update. You'd have a BitCoin Cash-like situation, the "birth" of a new currency with an initial airdrop... nothing more. Which one will be worth more is more difficult to predict, but ceteris paribus it will be the legacy chain.

      I think that is impossible because once the supply increase, the price of bitcoin getting low even there is a higher demand that's why there is a limit of 21Million of bitcoin to mine.