Cryptocurrencies besides Bitcoin are already moving on. By marketcap, the second through fourth-largest blockchains either don't use miners or are getting rid of them within a year.

Indeed. Honestly bitcoin is already outdated technology. It enjoys its current position by virtue of being the first and most well-known cryptocurrency. Ethereum and Monero are much more important technologies, I hope they'll one day be able to switch to cheaper proofs so that we can spend less energy as well as less money in fees.