Cultural, musical based idea;
The creation of operas and related musical genres (and shows genre) changed the path of what is occdental music, classical music, giving it somes very famous pieces - who never heard by example the Rides of the Valkiries by Wagner?
But it came as an odd idea, a fashion from italian states, mecenates of musicians and all, and was surely disliked by purists back then.
What if the mode never caught on, or died-never existed? At least, an obscure part of italian musical history. How would that have changed occidental music(s)?