I'm confused by these gold > all people here. Are you not using trade routes or what? I'm utterly swimming in gold because I'm not using an overly ridiculous military or running roads across continents. I can't figure out why you would need so much gold that you'd favor it over tech.
Having gold to buy buildings doesn't do you any good when you can't get the tech that unlocks said buildings anyway. Science gets you everything faster. Need a better military? Gold won't get you that. Gold will get you a BIGGER military, but it's not going to get your a better military. Need more culture? Gold doesn't get you that either. It gets you culture you've already unlocked, but it's not going to help you get to those broadcast towers and museums any sooner.
I don't even understand why this is a debate, honestly. Science is quite obviously so much king that there's no comparison. If you want to say you can avoid science and still win, well that's a different argument, but it's absolutely ridiculous to say that science is less important than anything else. I can't possibly be the only one who goes from Plastics to the information era in literally about 15 turns due to the stockpile of GS's I've achieved, partially due to a heavy focus on Science. Lets see gold do that.
As I said, gold is everything in this game. As you also pointed out, producing buildings and units requires tech (and I never said "ignore science") ... but that does no good unless you have the gold to actually maintain the stuff that you produce. Meanwhile, gold can be used to buy AND maintain anything you produce, as well as anything and everything else in the game. Having tech does no good when you cannot build anything even if you have researched how to do so.
If you have a weak military, the AI will crush you, at least any remotely expansionist/military AIs will.
Gold can easily get you military by buying units or allying/friending militaristic city-states. Science cannot do that. More importantly, on many maps, you need those CS allies to distract that AI civs or to counter their aggression, slow them down in their progress towards victory, etc. You need gold for maintaining alliances at a consistent rate. And yes, you need to support decent roads on many maps, obviously, while exceptions like Archipelago don't need them.
Plastics doesn't even matter for many games because you'll win long before then (or the AI will). As the prior poster said, you are looking way too late in the game to answer the OP's question or to respond to what I posted (i.e., gold is everything and Rationalism is not necessary at all, nor is it even preferred in many contexts as Patronage can give far more science than Rationalism). Saving Great Scientists? That won't do you any good once the AI crushes you for no defense. Also, as I explained, exploiting the game mechanics is not strategy. Regardless, it is quite easy to avoid Rationalism and generate plenty of GSes using other elements and choices, and that is what the OP was asking about originally (and what I and others answered).
The question is: "Are there strategies that do not have any need for Rationalism and are just as powerful, or even more powerful, than focusing on science?" The answer is yes, there are many such strategies, and there are many contexts outside of the player's control (e.g., map specifics, city-state specifics, AI civ specifics) where following such strategies is superior to focusing on Rationalism.
Aside from the exploitation of game mechanics and relying on abusing the AI bonuses for player benefit at extremely high levels, I think that the problem is that many posters tend to play a single way and think that that is the best way in all circumstances when it is not. Civ is a strategy game, after all, and allows for a lot of variance due to randomization. You may be able to still focus on Rationalism and succeed even though it is not the best choice in many situations, but many posters don't think of other choices out of habit, or so it seems when claims such as "science is king always" are posted.
Basically, you can focus on other things than science, and certainly avoid Rationalism, and still win easily (and faster than focusing on science/Rationalism in many situations) but you cannot ignore gold and win because everything in the game requires gold (except for World Wonders and the few buildings that don't have maintenance fees, specifically gold and defensive buildings).
There's a good reason why the AI civs almost always go for Banking, after all, rather than a different tech as their entry into Renaissance. If science was truly most important, then the AI would always go for Acoustics first.