I liked the flash forward aspects of the final seasons too. They often don’t work, but in this case, they really did allow us to see the full arc of Mrs. Maisel and co. without feeling cheesy or overly forced (for the most part).
Abe’s revelation towards the end about how he had been so blind to Miriam was, to me, one of the most beautiful moments of the whole show. Because you’re right — Abe was not a supremely functional parent to his own kids. It seems he tried much harder with his grandchildren, and especially Esther.
Thanks for reading!