It's always nice to see a show with a vision end on its own terms. Barry's final episode felt like the culmination of the entire show in a well crafted, tightly paced 35 minute finale that wrapped up all the loose ends and reminded us why this story was so amazing in the first place.
Barry is about A LOT, despite it's somewhat paint-by-numbers premise of an assassin trying to "get good" and embracing acting classes to restart his life. This show could've gone in so many directions, but the one it chose was, in my opinion, the right one. Barry is a tale about morality, about the human capacity (or lack thereof) to change, about justice and fairness. It's about Hollywood and how it acts as a magnet to attract the most selfish and narcissistic amongst us.
Barry is also a story about characters and this season represents the reckoning for all of them. Every character is embroiled in some sort of interesting moral dilemma that tests their character. Sally, Hank, Cousineau, Fuches, and of course Barry, are all put in situations where they can make a choice to do what's right or do what's expedient for them. Their actions have consequences and it's amazing to see these characters - many of whom started off as comedic and stereotypical (on purpose) grow and mature to become so complicated and fleshed out.
This season is also amongst the most visually, narratively, and cinematographically interesting of the show; it elevates the material with interesting storytelling and visual choices, a slow pace that the show knows when to snap out of, perfectly timed comedy, and a zany (but not over the top) vibe that straddles the line between comedy and tragedy.
I do prefer Season 3, which I contend is still Barry's best. The season does seem to run out of narrative steam at a point and doesn't have as much of the plot building that the last season had. But honestly, this show ended about as greatly as it could've.