Originally Posted by Captain Marvel
...you think Ultron taking over the worlds computer systems is on par with Thanos? Thanos became omnipotent more than once. He once murdered half the population of the entire universe. He recently murdered ALL life in another universe. In comparison to that, taking over the computer systems on Earth is so trivial it's not even worth considering.
They're not on par at all.
On a galactic level Thanos is head and tails above Ultron but with respects to Earth they both destroy you. One does it from the inside in a methodical fashion which lends itself to a more interesting and tangible danger the other goes ok your planet is done with the flick of his finger. The end result in both cases is destruction but one has much more backstory and impact when you consider where the threat originated from.