@carlesjove@mastodont.cat I can probably answer that for you, though im not a leftist I do deal in cryptocurrencies and many lefties WRT cryptocurrency.

For starters most leftists arent communists and most have no desire to abolish money all together. There are some extreme leftists who think that but they arent the majority at all.

The reason they like the state to not be involved really tends to be two fold (though not entierly consistent with their ideology all the same).

1) Anonymity for their finances. Particularly for protecting people who may work under the table.

2) This is the more important one, they seem to feel the USA mismanages money in a way that causes it to become devalued, or at the very least unfair. Obviously if you have money and the government can print more for itself and devalue you what you have, your less likly to want to hold onto that money as a store of wealth. There is a real fear of the US dollar collapsing. Meanwhile by having an algorithmic and fair process determine how money is printed, and at such a slow rate that it effectively causes negative-inflation satisfies their concerns in that regard.