No, parent is correct.

https://en.wikipedia.org/wiki/It_takes_two_to_tango

The meaning of this expression has been extended to include any situation in which the two partners are by definition understood to be essential (...).

since you keep saying that you are not a native speaker, consider believing the interpretations native speakers share. stuff simply means what it means. you can believe it or not.

more generally, when someone says something you find incredulous, consider processing that internally, and then decide if saying "huh, now i know" is not a better reaction to "no way, maybe you're wrong."

And you raised your objection, and got an explanation. That should have satisfied your curiosity.

Doubling down to say "This sounds so far out", and continuing to argue, doesn't really indicate curiosity.

I'm completely on the-dude's side on the reading of the original quote (not the tango quote) and I'm a native speaker. Moreover I find your (and the GP post) tone extremely condescending. There's no way to read the-dude's writing as "arguing". He states his readings of quotes simply without argument and clearly marking them as his personal reading (saying "to me" and "sounds"). By posting it here he's obviously inviting someone to explain why he's wrong - but the responses here are instead choosing to declare their authority on the matter and to belittle him.

And to the original point - he's not wrong. Of course from life experience we all know that there are exceptions to every rule, but the rule as written was that just a few stable adults suffices. Saying "it takes surprisingly few to tango" is completely different meaning from "it takes two to tango", so the comparison to that is not relevant (and the-dude does mistake that phrase, which is specifically used to call out that one is not enough). How many does it take? It takes surprisingly few. You have enough even if you only have a few.