No, it isn't, as my own and others experience prove. "All your GSes"... so, you are exploiting the game mechanics on high levels, that's basically what you are stating. I seldom get to Plastics before winning my games, therefore the tech is pointless since the game is already over. Even if I wanted to exploit the game mechanics, it wouldn't matter because the game is already over before I get to Plastics, at least in the majority of my games. Regardless, you can't have labs or almost anything else without gold to support them.
The problem with you is that you play a specific way that depends on taking Rationalism, but there are other, faster ways to win in many situations, and that is what the OP question was about (and what I and others answered).
You do not "need" Internet or Globalization when you finish the game before the Atomic Era or shortly thereafter. This is obvious, I think, so if anyone is posting false claims, it would be you, not me.
Yes, you need to complete almost the entire tech tree for a Science Victory, but that is NOT what the OP question was about nor was it what my posts detail. Why would anyone slog through techs to get to a SV when they can finish far faster with domination/culture/diplo (and with far less headache from the AIs cheats)? Only if you are stubbornly going for SV would you bother with this approach, but again that is not what the thread is about.
I'd suggest that you top posting rude posts, too, as though you're some absolute authority. I've seen you post similar rude comments on other threads claiming that your preferences are the only viewpoint. My posts answer the OP question by pointing out the fundamental element of the entire game: gold. Gold supports anything and everything in the game. Is Rationalism always needed? No, it is not, and it isn't even the best choice in many contexts. You have to play a specific way to plan to maximize what you can get from Rationalism. If you play a different way in many contexts, you can get far more from Patronage than Rationalism (and often finish the game far sooner).
Actually, the need for a strong economy for everything is very much a reflection of real life. Consider the crumbling infrastructure in America. We know how to build and maintain stuff, but there has to be money to do so, and there hasn't been sufficient funding for such work for years, thus the current situation.