Bitcoin has a version of that fund.
Every ten minutes or so, someone adds a new page to a shared record book. Doing that takes real computers burning real electricity, and whoever wins the race gets paid. Part of that pay is brand new bitcoin, created on the spot. That part is called the subsidy. The rest is fees, the amount people add voluntarily to get their payment onto the page sooner.
The subsidy is the town fund. It gets cut in half roughly every four years, on a schedule nobody can vote to change. Fees are the tips.
So the usual worry is whether the tips will ever be enough. I keep landing on a different question. Who ends up holding that new bitcoin?
Miners earn it. Most of them do not hold it. Power bills arrive every month and machines wear out, and both get paid in ordinary money, so a large share of every subsidy is sold almost as soon as it is mined. It moves from the miner to the power company, to the hardware maker, and on to whoever was on the other side of that sale. The subsidy runs as a slow steady auction, and the buyers are the ones who keep it.
That reframes the halving. Each one shrinks the auction. Less new supply reaches the market every day, and the bill for guarding the record book shifts further onto fees.
Fair pushback, and it has history behind it. Some miners are funded well enough to sit on what they mine and borrow against it, so plenty of the subsidy does stay put. And four halvings have come and gone without the watchmen walking off the job. Arguing that the next one breaks something is a hard case to make when the last four did not.
What would change my mind: fees staying a rounding error in miner revenue through the next two halvings while the network keeps running fine.
The schedule was written down in 2009 and has not moved since. Whoever is on the buying side of that auction is choosing to be there.
