But then again, we don't know whether this company is maintaining this infra themselves, or if they're paying for API access. Besides, if anything, running their own servers is often the more cost-effective option, so the details you mention might not matter in practice.
My incredulity has more to do with the profitability of this type of software, considering that the free options are good enough for the average person, and that the features promoted in the article are hardly innovative.
> There is no money to be made without whoring out your user’s privacy.
Well, I do object to that. It's certainly possible to sustain a profitable business without selling out your users' data. It may not be as profitable as the advertising model, which is often too enticing for companies to ignore. This company explicitly says that their income comes directly from customers, so apparently I'm underestimating the amount of people who find these features valuable enough to pay for them.