I think “should” — especially when found in its past tense construction “should have” — is one of the most dangerous words to utter and thoughts to allow yourself to think.
“Should” can’t exist on its own. There is no objective “should”. When something “should” be some way or another, that’s only true in relation to a particular standard, that’s not typically referenced or even acknowledged.
Why “should” is dangerous is that it’s easy to forget (or most people don’t know) that this standard needs to come along with it, and the “should” feels just objectively true. When one says “this should be easier”, “I shouldn’t have to work this hard”, etc, etc, it’s easy to feel like that “should” is just objectively true. But it’s not.