I think Universal should have refrained from using songs for the series. They felt forced and interrupted the flow of episodes.
You have a good point, especially in some sequels to the franchise.
The eleventh movie had a song that was pretty useless, and after it finished, cut to a different scene which explained the situation just like the song, like the song never happened, meaning that song was useless.
Then there was “Hot and Stinky” in the fourteenth movie, and why would we be singing if we are on an important quest to save Bron, this is important! He could be DYING!

Anyways, seeing as how this franchise became a musical in 1994, I can kinda see why Universal decided to use songs in the series.
Also, sorry if I go off-topic, but Phineas and Ferb did the whole “songs in episodes” thing better.