Most of the complex regexes I write fall into the category of stuff I don’t understand that might work. I’m no slouch at regexes either but when you start trying to do weird data processing stuff that handles all kinds of edge cases the wheels really come off quick.

...and that's where you stop using regexes exclusively and start using better parsing techniques.

If you write it you at least partially understand it. I don’t buy it

If gpt writes it and I don’t understand some parts I just paste it into a regex testing site and examine the groups and try it out with different snippets of text. Is that so hard? Is it any different from using something you found on SO?