So BTC will continue to be mined until about 2140, when all 21 million are finished. But imagine if there were 21 trillion bitcoins and it finished in say the year 9140, it actually wouldn't make any difference to us than 21 million, because the inflation rate would still be the same. I think the current bitcoin inflation rate is 1.3 percent or whatever. So just imagine if there were 21 trillion bitcoins and 18,648,168 BTC were currently in circulation, do you think people would still say you know there will only ever be 21 trillion bitcoins.... i dont think so. But it would be the same as saying there's only 21 million. Maybe in the year 2130 people can say that when there's only 10 years left but for us who are alive now, why should million or trillion matter. Inflation rate and circulating supply would still be the same.... any thoughts?
What matters most is, of course, the circulating supply, so you're right that under the circumstances you described, 21 trillion bitcoins wouldn't make a difference. The only difference would be in perception, but that difference could have a major impact. The appeal of Bitcoin is largely based on the fact that it's perceived as scarce. If people knew that we've mined a very tiny amount out of the total supply, it would be discouraging and feel like Bitcoin would eventually lose its relevance due to being overabundant. And this could become a self-fulfilling prophecy, making people lose interest in mining and using Bitcoin way faster than it could've actually reasonably happened in a thousand years from now.