The series finale is premised on a certain notion of "realism" whose possibility and normative appeal are quite unclear. Successful criminals do not get caught and do not present themselves to the writer's room to brag about this. Then, how do the writers know what is realistic? And even if the writers (and their consultants) have been steeped in the criminal underworld long enough, most viewers probably have not been and, so, will not necessarily regard the writers' realism as realistic.
The normative appeal of realism is questionable. If society is stuck at a bad equilibrium, it is hardly noble to seek to reinforce this equilibrium by remaining true to it, by remaining "real." Realism in this normative sense is conservatism, which has limitations.
While realism carries little normative significance beyond reinforcing the status quo, internal consistency of the narrative is aesthetically and intellectually pleasing and, therefore, does belong in a work of art.
It would seem that internal consistency itself would call for realism by insisting on the realism of certain behavioural rules of logic, such as "If Alice is the kind of person who habitually does X, then she will never do Y." This may be so, but these rules of logic are less arbitrary than the rules that call upon the fate to punish the purported transgressor or to summon the prevailing notions of morality in order to energise the mob to meter out justice as it is currently understood. Furthermore, internal consistency does not require the rules of logic to be realistic. Surrealism, abstract maths, and quantum physics are among the examples.
Even though the last season is botched to please a committee, the work executed within these constraints is superb throughout the series. (The last season is botched in that internal consistency is violated: Marty acts out of character and fails to reveal the depth that the rest of the series was busy cultivating. In the final episode, Ruth is killed off in the name of "realism.")
Julia Garner consistently shines in every single frame she appears. Jason Bateman bets on rejecting histrionics for his role and wins. Someone should shoot an alternative ending or at least fork the ending on a fan fiction website.
And there is also potential for a musical, although the show's creators may not see it today.
