This is called the golden mean fallacy.
https://en.wikipedia.org/wiki/Argument_to_moderation
https://www.logicallyfallacious.com/logicalfallacies/Argumen...
What I've found as I get older is that when someone says "It’s really simple," that's a good sign it isn't.
Something can be really simple, yet very hard. Like saving money or losing fat and building muscles.