The most tragic example of this is that Mike, Liz and April lost out on getting to know one another growing up. While Michael might think that he knows who Liz and April are, he hasn't got two clues as to who they are, what they want and why they want it because he sees them as being what his fear of having everything taken away from him and being lectured about being a horrible child who's a huge disappointment that Elly and John regret having make them into. Trying to sit him down and explain to him that Liz only does all the crazy crap she does because her sullen dickwad older brother hates sharing would be futile because he doesn't realize that they should never have been at war in the first place.
Similarly, Liz has yet to realize that instead of being the Son who will always shine in her eyes, Mike perceives himself as fighting for his very life against a usurper who clearly must hate him and want him to suffer and bleed and die alone and unlamented because she doesn't see the poor fool Mike really is.
Thirdly, no one sees April as the universal target of scorn and harrumphing about being a princess she is. Instead, some idiot makes a facile non-sequitur about how April fools all of us which highlights how they've bought into Elly's insane, self-serving ranting about how the Martian deliberately arrived to ruin everything because she hates her pooooooor mother.
The only real solution to the problem that I see is for Elly and John to die as quickly as possible. Having the final, desperate fight over belongings Jim kept Phil and Elly from having would clear the air and get three broken people to see one another clearly for the first time.