Conversely, non-technical business people are very highly likely to tell me some piece of engineering is "easy" or "simple" when they have no background, or knowledge, at all.
Anything requiring invention by definition is not straightforward because its potential timeline may be functionally infinite if it cannot be solved with the tools at hand.
A task like changing all APIs to accept a different set of parameters might take 6 months, but is straightforward.
"Easy" is the one line change that has no side effects, and is uncommon in practice. After all, sometimes it is that one line change, but there are ramifications elsewhere in the system that need to be thought through.
And when an engineer says something is hard, sometimes it's because they've done it before, and it really really sucked and burned months of their life and can we please not talk through the details that still make me cringe?
And occasionally there's that one engineer who describes stuff as "simple" after watching an old Rich Hickey talk.
Some things are simple, some are complicated or complex. The degree of difficulty is basically orthogonal.
Running a marathon in under 2 hours is incredibly simple. All you have to do is pick a point 26 miles away and run in that direction. But it sure isn't easy.
"I'm retired."
"Wow, that sounds really hard!"