How is one different than the other? There are many jobs that you would consider "normal" that are far more dangerous (e.g. logging or deep sea fishing), or where you are treated with much less dignity either directly (customer support, etc.) or indirectly (a modern warehouse job where you are a glorified manipulator attachment); in almost any jobs, workers could be exploited, trafficked, etc.
What in particular (with some basis in physical reality) makes sex work special compared to all of those?
Sex is something women do not generally give out easily, especially to men they are interested in dating for the long term. Sex is also an intimate act that strengthens the bond between a couple. By selling sex, the woman devalues herself in the eyes of men. Why do women make guys wait for the Nth date before they have sex with them, if not for the sole purpose to make the guy think that the woman is of high value? You know, that she doesn't just sleep with anyone just like that.
Ask yourself this:
1. Would you marry or date a woman who does sex work?
2. Would you be OK with your daughter/sister doing sex work?
Then ask yourself the same questions after s/sex work/software engineering/g and tell me if you get the same answer.
All of the rest comes down to baseless mental hangups, although e.g. withholding random sex has basis in safety considerations. There's also reputational damage, but that cannot be used to to justify reputational damage, that would be circular. It sadly has to be managed, though, so even those without mental hangups and safety concerns might withhold sex.
The answers are "yes, probably" and "yes, if that's the best option in terms of income and safety". To the extent that it gives me pause, I can recognize those are just bugs in my thinking. It's often helpful to analyze your reactions and conclude they are broken, not trust your gut with no justification, e.g. instinctively get angry when someone cuts you off in traffic, or in this case are instinctively disgusted by sex work.
if you want an even more bulletproof argument you could add that most tech workers are overpaid because they are benefitting from the rents/royalties extracted from intellectual property by the propertied class