Wildest of all to me is that some networks add even more ads above and beyond what an older show was produced for, leading to running episodes at slightly faste

Wildest of all to me is that some networks add even more ads above and beyond what an older show was produced for, leading to running episodes at slightly faster speeds to fit in that extra ad break. TBS was infamous for doing this with episodes of Seinfeld, you can find them side-by-side with the original speed airings on youtube.