One thing about the What If…? series that has been really interesting (and I’m sure a little controversial for some) is the use of the characters. Some characters have been utilized in ways very similar to their inclusions in the MCU from a power level while other characters have either been made much weaker for comic relief (like Thanos) or given overdue chances to shine (like Captain Marvel.)
But Ultron. Oh-ho, Ultron is on a whole other level of scary in this series. In this series, the writer A.C Bradley imagines a universe where Ultron had actually won. Ultron ends up easily obtaining the rest of the Infinity Stones by merely cutting Thanos in half with a nanosecond Mind Stone blast. It was shocking to many and more than a little bit unbelievable but it’s honestly not as far-fetched as it seems.
Think about Vision and the few instances where we actually got to see the potential of the heroic synthezoid.

When he first appears in Age of Ultron he’s so powerful he picks up Mjolnir as if it were nothing, shocking the Avengers as they suddenly realized just how incredible the Vision was.
It is, unfortunately, only in Age of Ultron that we see Vision at his most powerful as he uses the Mind Stone to not only shut Ultron out of the internet across the globe but we also manage to see him use the golden-blast machine in his head to devastating effect against Ultron’s robot lackies.
They disappear in golden beams of Mind-Stone light and he uses his phasing ability to reach into the robots and rip them apart. It’s impressive, especially considering that he seems to only be on the cusp of his potential.
Unfortunately, at the time, he was too powerful compared to his fellow Avengers and because the writers had no idea what to do with him they weakened Vision exponentially in Captain America: Civil War, turning him into nothing more than a vessel for romance with Wanda rather than allowing him to be the ultimate wrecking machine that he is.

In Infinity War, they immediately take him out of the equation by having Corvus Glaive stab him, thus weakening him to the point where he can barely function. So no, we weren’t able to see what Vision could do at full strength hence we’ll never know whether Vision would’ve actually been able to merely cut Thanos in half among first sight or not.
Instead…we had to watch Vision die…twice.
Now we have White Vision. Maybe we’ll finally get the chance to see Vision’s incredible potential instead of being nothing more than one half of a very stirring romantic relationship with Wanda.

And think about it. The same goes for Ultron who was also terribly weakened in the movies because, technically for all of the above reasons, he was way too powerful a villain to be in the MCU at the time and the writers knew they had messed up.

So What If…? isn’t taking the strength levels of Ultra-Vision (that’s what I’m calling him now) to unbelievable heights. We’re just finally seeing these characters get the power-level recognition they deserve.
I thank you for reading and I hope you have a spectacular day.