Big stories need big villains, and “What If…?” finally cemented its bad guy in “What If Ultron Won?” Having established round-the-clock quiet hours for all life in the universe with the help of a full set of Infinity Stones, Ultron’s consciousness developed to the point where he could see the otherwise nebulous Watcher, pierce the shell of his reality, and make a move on the Multiverse in the name of “peace in our time.”
This tells us lots of things. First and foremost, Infinity Stones work outside of their own realities? Their own timelines? So why did the ones in the drawer at the TVA do fat nothing during “Loki?” On top of that, we learn that the Watcher, who comic fans already recognize as a formidable force in the universe, has the gumption in the MCU to stand up to the Infinity Gauntlet.
But most importantly, we now know for a fact that the “What If…?” universe threw away a perfectly good realm of never-ending possibilities by making Ultron the main villain of the season when, in an unceasing hall of mirrors reflecting all that ever was or could be, there was absolutely a timeline where Bob Ross used the Tesseract to reign supreme. Overlooking that option was an unhappy accident.