I am not a security expert; I'm sharing my experience, not attempting to answer the question. Back before I used a good password manager setup, I used a mental

I am not a security expert; I'm sharing my experience, not attempting to answer the question. Back before I used a good password manager setup, I used a mental algorithm of [base password] + per-site modifications. These were saved in Firefox and I'd sometimes forget them when I wasn't on my normal device. If I needed to get on to a service (eg, email) whose password I'd forgotten, I'd reset it, then reset again, back to what it was, when I got back to a place it was saved. At some point, gmail prohibited this, and I had to update all my passwords whenever I needed to reset. The result was the same as forced password rotation: I just started using more memorable (less secure) passwords. That said, there's definitely measures Google could take to mitigate this effect. For example, drawing from the article, there could be tiered access control, where one tier (eg, 2fa but no pw) lets me get some limited access without changing the password. Then there would be no legitimate reason for returning to an old password, so such a policy is not harmful.