Apart from timing, and the general dynamics of the “popularity” phenomenon, It has also been suggested that politics had a part in it as well; more specifically, that influential people “strongly suggested” that the saxophone had no place in the classical orchestra. Makers of more traditional woodwinds, IIRC…? Don’t know how much truth there is in that, though.
There are similar theories about why the violoncello da spalla was abandoned and practically forgotten, despite having clear “agility” advantages over the modern 'cello, due to being able to use violin/viola style fingering. Some claim that composers were not allowed to write specifically for what was supposedly the 'cello of the time - the violoncello da spalla - so, much how you avoid legal issues by making vague references these days, they just wrote “cello” or something - and a few hundred years later, cellists are still having a really hard time with certain passages. I don’t know how much law/politics was actually involved, but it all seems to make some logical sense. And either way, the now revived violoncello da spalla is a pretty interesting instrument!