They want to monitor your behavior (mouse movements, clicks, etc) site-wide so they can determine whether you're a bot before you get to the "protected" page. So the carrot for the website owner is that people that don't want to solve "click all the stop signs in these 9 pictures" challenges don't abandon your forms because they're never challenged, at the expense of adding behavioral tracking site-wide.

So that they can watch your interactions with the site to confirm that you do it in a “normal” way, nevermind that this discriminates against those with disabilities.

Blocking scrapers?