For long, Bitcoin has been touted as the "store of value" of the crypto/Blockchain space with its limited supply of 21 million coins. Based on estimates, all Bitcoin will be mined by 2100. Now, what if developers decide to increase that hard cap in supply? If at that point in time, Bitcoin's prices stay just the way they are right now (less than $1m), it may become unprofitable for miners to continue supporting the Blockchain. With no block reward, they'll be living off fees. If prices are too low, earned fees won't be able to sustain miner's operations. By then, developers would need to raise the limit of 21 million coins to a higher value, re-introducing a block reward in order to attract miners into the Blockchain. Otherwise, the security of the Bitcoin blockchain will be at risk.
Do you think that the need to increase BTC's max supply will arise in the future? Or will Bitcoin be able to "live" just fine with a max supply of 21 million coins? Your input will be greatly appreciated.

If it did then what would be the difference between BTC and any FIAT currency? If you think about it, there would be no difference since you cannot say that it is anonymity since it is increasingly regulated and will continue to be. So that's why I think the MAX SUPPLY shouldn't change. Only time will tell for now deflation has been working. Just look at its price and see where it started.