"Using your example, if you were starving and someone offered you money to mow their lawn, would your being desperate make it slavery? In fact, aren't most of us starving were it not for our jobs? Don't most people work because they need the money to survive?
There is no difference between buying consent to mow a lawn or have sex. As long as the person isn't being pressured or coerced, it's a consensual transaction."
Do you honestly assign the same meaning to having sex and mowing a lawn? We can sit here and pretend it's all the same, but we know it's not, don't we?
No one ever finished mowing a lawn and threw up because they felt degraded or dirty or objectified from it, did they?
Whether it is cultural or something engrained in us, sex has a different meaning to most other activities. It is something that makes us feel vulnerable.
Maybe if we lived in some kind of Brave New World style utopia, it would be different, but we don't. We live in this world. Pretending it's the same as mowing a lawn is completely disingenuous.