"There’s no security issue — the is growing, that means everything is okay!"
The output of Proof-of-Work isn’t hashrate — it’s economic cost. What matters is not how many hashes are produced, but how expensive they are to produce. A growing hashrate means nothing if it's powered by cheaper hardware or cheaper electricity.
In other words, security doesn’t come from numbers on a graph — it comes from real-world costs burned to defend the network.
If the BTC-denominated rewards drop, miners may still produce high hashrate — but with fewer incentives to stay honest. That opens the door to cheap attacks, especially if the cost of hardware or electricity falls. It’s not about how much hash you see — it’s about how costly it is to fake.
"The price of Bitcoin will rise, so even a tiny subsidy — like 1 satoshi — could still be worth a lot in the future!"
This logic is flawed. The security budget must be evaluated in BTC terms, not in USD. Miners are paid in BTC, and attacks can be funded in BTC. It’s unreasonable to expect that an economy worth 2,100,000,000,000,000 satoshis can remain secure if it only spends 1 satoshi every 10 minutes on defense. If miners are underpaid, they can simply be bribed with BTC, regardless of how high the USD price is.
"But the cost of an attack is more than just the security budget — you’d need to buy ASICs, hardware, etc."
That’s true only if the attacker builds everything from scratch. In reality, existing miners can be bribed or incentivized to cooperate. If the network underpays them, they may find betrayal more profitable than honest mining — especially if there's no long-term reward to stay loyal.