Yes, free money inflates risky assets, but it's also just supply and demand. Mining rewards got halved, so miners can't sell as many BTC as used to do after mining a block, so the supply of BTC just went down significantly.

The more macro stuff like worries about inflation due to the Fed printing $$$, easy money (0% interest rates), and yes, some FOMO speculation is increasing demand.

As far as I'm concerned this is working as intended. This is not the first boom / bust and this won't be the last.