Do you imagine this is how the workers feel about it? Do you think they tell their friends "I seduce western men online for pennies an hour" the same way they'd say "I am a waitress?" You can ignore this fact if you wish, but these jobs carry a social stigma and most people would prefer not to role play intimacy with men online if there were another option.
"Sex work is work" is like saying slavery could theoretically be OK under some circumstances (We're all born under legal obligations, how is slavery different etc etc.). A tortured theoretical argument could be made to support either of these, but in reality we know that slavery is unconscionable because of the indignity and brutality of it, regardless of theory. "Sex work" is the same: in reality it is a dangerous and unpleasant job (that overlaps with slavery a lot, incidentally) done mostly be vulnerable women, and that they're often abused and left injured by it. See this article before you go saying prostitution is benign and harmless, this stance is divorced from reality: https://www.spiegel.de/international/germany/human-trafficki...