Bringing up the Transformers is an odd comparison... MCU has at least ten movies with great critical reception. Transformers has 1 with the Bumblebee spin off and it was hardly as popular as the most acclaimed MCU films.
BoX office wise, Transformers isn't even close.
Also in terms of impact, I can't think of any long lasting impact Transformers did to the movie industry, when their movies were still popular? Mcu pretty much defined the 2010s decade in movies, with its popularity. Remember the time when other studios were trying to launch their cinematic extended world.