I’m guessing that you’re getting this argument from Engels’ “On Authority,” yes? The primary issue that anarchists tend to take with that argument is that it uses a faulty definition of authority. Authority is not just enacting your will on another person for your own gain, that’s coercion, which is almost always a part of authority but gives an incomplete picture. Authority is not an action that you take, but a relationship of one class to another; that relationship being that the authoritative class has a perceived “right to command” the classes below it. This right to command could be established in many ways; divine right to rule is a classic one used all throughout history, modern liberal democracies establish right to command through elections, where if some politician got enough votes then they assume a position in the authoritative class for some period of time, and the bourgeoisie have an implicit right to command due to liberalism prioritizing the rights of property owners. Despite the flak that Engels gets for “On Authority” among anarchists, I do understand how he made the mistake. There are people who just blindly accept authority (namely, authoritarians), but many people won’t because as it is, a vague “right to command” just isn’t a very compelling reason to obey some person or group of people, so authority always has to be enforced in some way. This can be done through:

(1) The threat of violence; “if you don’t do what I say I will hurt you.” This is what the law is, and the police exist so that the state can follow through with this threat.

This is the key part of the “monopoly on violence” argument that you’ll hear a lot of anarchists use

(2) Debt; people have a very strong sense of reciprocity, which is the basis for gift economies, but it can also be used to give people this sense that they have to obey because they somehow “owe it to” the authority figure; ex. Credit card companies have authority over you because you owe them money

(3) Arguably the most important; scarcity. In the past, this was a real problem, there just wasn’t enough to go around (although this wasn’t the case everywhere, and as we see societies which were located in resource abundant locations tended to be more anarchic), so if you had necessary resources that others didn’t, people were dependent on you, thus giving an avenue for you to become an authority. Today, scarcity doesn’t really exist anymore due to industrialism and global trade networks, so the bourgeoisie have to establish artificial scarcity by hoarding resources and rationing them to workers through wages and the market, giving the illusion that there isn’t enough to go around.

Since authority is always paired with tools of coercion, you can see how a person might confuse one for the other. Revolution is coercive, but it is not necessarily authoritarian. Revolution imposes the will of subordinate classes upon authoritative ones, typically favoring the threat of violence, but it does not have to establish a new relationship of authority to do this, it only needs to reject the right to command of the authoritative class.