Bitcoin is _not_ magically produced by the sun striking the ground.
There are mild returns to scale in running large-scale mining operations and as a result mining power seems to actually be somewhat centralized under the control of a small number of players: https://digiconomist.net/cryptocurrency-decentralization/
Not to mention that "decentralization" is a technical property and not necessarily desirable in itself. Users might care about fairness, avoiding sanctions, purchasing illegal goods, etc, but these are only weakly connected to technical decentralization.
In March 2023, the New York Times identified a list of
just 34 Bitcoin mining facilities (controlled by 22
different entities) in the United States, which
represented about a third of the total worldwide
Bitcoin mining network at the time.
If we extrapolate from that, it would be 66 entities that control 100% of Bitcoin mining. Miner revenue is somewhere about $50M per day. So on average one of those miners makes very roughly $1M per day, say $365M per year.
34 such $365M/year entities would have to collude to attack bitcoin. And accept that their business is severely damaged afterwards.
So much for the decentralization and security of Bitcoin.
There are mild returns to scale in running large-scale mining operations and as a result mining power seems to actually be somewhat centralized under the control of a small number of players: https://digiconomist.net/cryptocurrency-decentralization/
Not to mention that "decentralization" is a technical property and not necessarily desirable in itself. Users might care about fairness, avoiding sanctions, purchasing illegal goods, etc, but these are only weakly connected to technical decentralization.