How to mishandle an interesting series / movie ( For All Man Kind )

we're going to talk about how you can mishandle an interesting concept on the occasion of For all Mankind (probably spoilers for anyone watching)
I watched all three seasons, mainly because I'm interested in alternative history as a theme. In this case, the concept was that the US loses the space race, as the Soviets send the first man to the moon, just months before the famous Apollo 11 mission leaves. The Americans get columbra, and we see a very different development of how the two superpowers tried to conquer space.
Interesting so? But come on they didn't manage it properly. While the first season had a good interest, maybe suspense I would say, from the second onward we see that they are spent on interpersonal relationships, who slept with who, who didn't sleep with whom, with a few nuggets of some interesting points. Gradually the series goes downhill, both for the Americans and for the Soviets and somewhere there is a crazy guy who plays entrepreneur and wants to send the first manned flight to Mars. I mean, there you go, bro.
My question is, why is it so hard to build a real and meaningful narrative around interesting ideas? E.g. The Purge. Why is it difficult to pose big questions even within the context of alternative history, which is still a branch of E.F. (and we all know what EF is capable of)?
In the series we see (1st ep. I won't spoil it) that from the moment the Soviet moon landing takes place, the Americans are in a phase where we will not put our heads down, we will rebound, and like the true underdogs that we are, we will win the race. Oops, tall man, deal with something that can also be described as a collective trauma. When Gagarin was sent into space, the entire US went into hysteria and thought that now the Soviets would be watching them from space. In other words, give some juice to a particularly intense period for the USA (defeat in Vietnam, civil rights, MLK), don't tell us 'what the hell we are, we will win'. As I said before, this thing becomes intense from the second season onwards, as the trip to Mars from a collective event becomes something very individual and personal. What happened; Couldn't they handle such good material and resorted to clichés? I could pick up other points, but I think you get the general idea.
So tell me, what good TV and movie concepts were wasted in your opinion?