the devs are the ones that decide if they will make changes on thier coin . for bitcoin , bitcoin core developers and not the majority or the ones that hold alot of bitcoin .
but i dont know if its possible to change the supply of the coin once they were already released and running . if yes then i still think that it was not easy . laslty , i dont think that its beneficial to up the supply of btc because that will only make its price lesser but that would make bitcoin more stable .
No, if its not accepted people won't upgrade their nodes and the network would remain with the current rules. Its not as simple as developers simply pushing the change. Most improvements are minor and tacitly accepted, but if something this controversial would come you can expect a hell lot more of resistance.
Yes its technically 21 000 000 x 100 000 000 = 2100000000000000 satoshis, to be objective the OP would be asking, if they could change this into 4200000000000000 satoshis.
Everyone knows 42 is the answer. As for the question, you'd have to read a book, actually a guide... Something about mice running an experiment... (Douglas Adams actually said he didn't pick 42 for any specific reason, but this joke is endless).
As for the reason Satoshi used 21, i guess, it was the same (arbitrary). But most importantly, it was set and accepted as the rules. If it were 42 since the beginning, the result would be identical, bitcoin price would be exactly half, and people would have exactly twice of them. You could also do the opposite but i see no reason to change the rules at this point.
