What’s the deal with one shot combos?

I know everyone makes the Overwatch comparison but there is not a single hero in that game who can one shot simply be exhausting all of their abilities. It’s absurd to me that these “High Skill Characters” like Spidey, BP, Psylocke, and Magik can all one shot a squishy simply by using every ability in their arsenal. I know i’ll get a bunch of shit for this but those five characters take no skill. All you have to do is learn like a 4-5 button combination and you’re guaranteed to get kills, it’s absurd.