In our opinion, cloud mining is the most convenient way for it.
Cloud mining is the best way to lose money, don't fool people with false promises because you won't do well on this forum - we know it is 100% SCAM.
Actually everything in Bitcoin can be changed, as long as there is the consensus for it.
Everything is subject to change, but as others have commented, anything that would interfere with the basic features would actually be the creation of a new coin - and the original Bitcoin should just stay at its max supply, so Satoshi determined, and it should be respected. If you want to see what happens to alternative BTC that have a max supply of tens of billions best to take a look at all the BTC forks ->
https://forkdrop.io/list-of-bitcoin-forksNo matter what, the original will always be what people follow the most - it is the only decentralized solution in the literal sense of the word - all other crypto projects have someone who manages them in their own interest.