If you really hate a company, you won't delete your account. You'll run spam on that (verified human) account or sell it to some third party who wants an account for spamming.
I mean, these companies are themselves providing the tools to mass produce what would be labelled “spam,” the topic of the OP itself.
Deleting your account may not make even a pixel of difference in their KPI graphs, but -in addition to the mental benefits- you get the moral one of not being a participant in this mess…
They make money from your spam too, at least in the short term.