There's no accounting for niche preference of course, but at less as far as understanding the feasibility of an approach like this: I don't think most people have the "cut off their nose to spite their face" impulse that you're describing here: if a captcha is more usable for the user _and_ helps the company, most would just see that as a win-win.

You do use your computer power to solve math but it doesn’t benefit us in any way. We don’t use it to train any AI or anything like that. We don’t even store personal information. Just aiming to be a simple one-click tool so it has to be computationally difficult.