Its products have been the standard foundation of computing for decades, they're so ubiquitous and entrenched. Although growing up with PCs using Windows it was mediocre: slow, bloated, unintuitive, you learned to wait after a click to let it "think". Doing anything on Azure is an endless maze of "pull your hair out in frustration" astoundingly bad, everything so overly difficult. And Teams.
It's depressing that despite it all it became the standard, yet encouraging for the quality software that will one day supplant it...