They might think that, and they might be right. There have been multiple accounts from sec workers who feel friendly to their clients.

Think about any place you go regularly: you might have a friendly relationship with the cashier/waiter/barista/bartender/whoever. That relationship only exists because you are a customer, but that doesn’t mean they don’t feel genuinely friendly to you. When I’ve worked in service jobs, there were plenty of people I only interacted with because I had to, and there were a handful of people I genuinely liked seeing. Just because someone is selling images of their naked body and a sense of intimacy doesn’t mean the dynamic is fundamentally different on their side. For the clients, there is often a misunderstanding of what the boundaries are, which is why many sex workers are extremely direct with people.