Is it? I feel like most of my atrocious cookie hand fix cases end up being broken redirects where you get redirected to some new url that errors, so loading the page doesn't help to get rid of the offending cookie.
Manually interrupting most flows is practically impossible. Too fast, and can chain across a half dozen (sub)domains near instantly. The web hasn't been that slow or simple in a long time.
Yes, as mentioned, from atrocious engineering.
See also that Windows can break the desktop due to their own advert.