> the performance degradation was _very_ noticeable, causing years of comments on Apple intentionally obseleting old devices by slowing them down.

You just disproved your own point. This throttling was only implemented shortly before it got noticed and Apple announced it’s existence, like a couple of months at most. Apparently it wasn’t ‘very noticable’ and the perceived slowdowns were all in your head because for all those years you claim this was going on, it wasn’t.