Hardcore socialists apparently think that’s true. After all, if the other person wants it, they must be taking advantage of me! They all operate from a fixed pie / scarcity mentality, and must have missed the basic economics class where you learn that parties can trade where ALL end up better off than if you didn’t.
Of course, but it’s hard to argue that because a trade is advantageous to you, you cannot attempt to create the conditions where it’s even more advantageous. And in negotiations, you should strengthen your BATNA (best alternative to no agreement) and that of the other party’s. So you could see class struggle as a strategy to improve the starting positions in a negotiation, if that makes you happier :-)
A mugger doesn't steal from me, if I hand my wallet to him, right?
Analogously to how this is theft because of the threat of violence, so it can be argued that it is also theft/extortion due to the threat of leaving you and your family homeless and starving if you don't take my offer right now.
There’s a market for labor too, so it’s not like most people have only the choice of one employer’s offer or starvation. And no one is arguing that we shouldn’t have a social safety net of any kind to improve the BATNA of employees.