I just revisited the anime today for nostalgia, and I was thinking about how, as someone who has read the manga, the anime should have been 3 seasons and not just 2, pacing wise

Don’t get me wrong, the anime was a brilliant adaptation of the manga imo, but a manga reader would know that the second season was a little rushed. After all, the series is split into 3 terms and the first season covered the first term, it would be natural to let the second season cover the second term and the third season cover the final term. Since third term is a little short, maybe make it a 12 ep one, still more room for the 7-8 episodes we got. And that way second term can be extended from 16 episodes to 20-22. Also, the kaede kayano/korosensei past arc would have been a good closure to the second season.

But then again, there might be business/logistical reasons beyond control - but would like to hear your opinions.