First block of proof. (I explain, why BTC in current state doesnt have future of 20 or 40 years, when all 21M BTC will be released, It will end much earlier).

It is no secret, that solving blocks is getting more difficult and that is happening in exponential rate.
https://bitinfocharts.com/comparison/bitcoin-difficulty.html

At the same time, profitability of mining vanishes into zero. It has ROI negative in most of countries already.
https://bitinfocharts.com/comparison/bitcoin-mining_profitability.html

At the same time Hash rate grows and grows.
https://bitinfocharts.com/comparison/bitcoin-hashrate.html

Its a common myth here, that vanishing profitability of mining is covered by transaction fees, but that is far from being true.

https://bitcoinfees.info/

Conclusion: mining is getting more and more pointless and that is happening in furious pace!