https://markets.businessinsider.com/currencies/news/bitcoin-price-cryptocurrency-should-be-curtailed-terrorism-concerns-yellen-2021-1-1029985692
The authoritarians (socialist, fascist etc) know that something like bitcoin will curtail their ability to:
1. Print money to debase and secretly steal money from people through inflation.
2. Control all uses of money in order to shut down debate.
3. Take assets across borders preventing their ability to control it.
In short, bitcoin and p2p software will undermine their ability to control, rule, tax, and eventually destroy with their policies, the world. Bitcoin gives people power over themselves, power to control their own destinies and the power-hungry elite do not like it.