Bug bounty payouts correlate with how secure software is (more securely written software = larger bounties).

Your answer would be:
OS: Desktop < iOS < Android

Mobile: all other browsers <<< Chrome & Safari

Desktop: all other browsers <<< Edge & Safari & Firefox < Chrome

I agree AI is a godsend for non coders and amateur programmers who need a quick and dirty script. As a professional, the quality of code is oftentimes 💩 and I can write it myself in less time than it takes to describe it to an AI.