Dearly beloved, we are gathered here today to get through this 80-minute season finale, and what a ride it is! For All Mankind’s fourth season has been a bumpy watch at times, as some characters were underserved (Kelly and Dani, in particular), others were given too much screen time (Ed and Miles, I’m looking at you), and undercooked plotlines were forced to unfold before their time (Happy Valley strike, we hardly knew ye). “Perestroika” takes some big swings at wrapping up season four’s core themes of the pluses and minuses of pursuing progress, class struggle, and the use of excessive...