That one seems to correspond less to "money put in" though. As they note, just having Satoshi move his one million bitcoin would increase Realized Capitalization enormously, even though no new money is put in.

Sum of daily price times daily emission on the other hand represents the total miner revenue; how much they would have made if they sold their mined coins as soon as possible (ignoring coinbase maturity for simplicity), which presumably upperbounds the total amount of money spent by miners on hardware and electricity.

Good point, although your algorithm sounds more like it measures a lower bound on miner revenue, since it doesn’t account for miners who avoid selling their proceeds when they perceive the exchange rate to be too low. It also doesn’t account for future transactions of the same coins, so it doesn’t really address the entire market, only mining revenue.

Realized Cap isn’t perfect but it seems like one of the most useful attempts at measuring market cap so far. Of course “usefulness” depends on the question you’re trying to answer. Other factors can be taken into account, like the Free Float Supply: https://coinmetrics.io/introducing-free-float-supply/

Also keep in mind most of these calculations only consider on-chain transactions. Funds could be sitting unmoved on chain for years while being transacted many times per day on a second layer: Lightning Network, “wrapped” on another chain like Ethereum, or traded between participants on the same exchange.