In my opinion, Bitcoin mining is meant to come to an end, knowing that the number of bitcoin is limited, miners knows this, as well as the whole cryptocommunity, But it doesn't dictate the demand of bitcoin, if the consumers continues to value bitcoin or any other cryptocurrencies then the cryptocommunity will continue and bitcoin will survive. Of course by this time, bitcoin miners would have definitely find another way of earning money. I think even though the miners have completely mined all the bitcoins out there, the crypto world would continue.
Bitcoin supply is limited, but I am sure that not all Bitcoin will be able to be mining with the assumption that mining costs will be even greater, while now prices are falling. The period of earning money from mining is certainly no longer a profitable thing.