Ok, so you have this computational power for generating this keys but what it should be the "real life" use of these private keys?
I mean, these are not email or something that "change the password and now is your".
these keys are clearly known to another user, why someone would ever use this? and why such huge numbers?
I guess probably some people want to accumulate and monitor the activity of as many private keys as possible, in the hope of being the first to be able to sweep funds if deposits are ever made?
Even if it's a big waste of time... (Not to mention that people who can keep a server running 24/7 to monitor addresses are generally able to generate as many private keys as they like, so I don't understand who could buy bulk of keys to OP...)
It reminds me websites like keys.lol and others.