So a few notes here. Its less authority versus everything as it is Warfare vs everything (which obviously authority helps you war).
Warfare has always been an OP strategy in civ 5, for a few key reasons:
- The higher the difficulty, the better the AI's stuff becomes. When you war, you both gain this large amount of stuff, and deny it to an opponent. There is no equivalent to that in peaceful play. With peace its "I win, and my opponent wins....and we will see who wins more". With warfare its "I win, and they lose".
- The nature of Civ 5 warfare. In civ 5, smart human players rarely lose troops, good tactics and smart positioning allow units to become "immortal". Therefore, an initial investment in military can reap nigh infinite rewards over the stretch of a game. Contrast that with Civ 4, in which in warfare both sides lost scores of units, as the two Stacks of Doom threw themselves at each other, and you had to sacrifice tons of siege engines to soften the defender up enough to actually make an attack. A player using their army to war is gathering a whole second set of resources (experience, pillage gold, new cities, unit kill bonuses with authority/terracotta army), and if they are playing well, will suffer a pretty low cost for that army. Two economic engines are better than one.
That is not a VP thing, its a Civ 5 thing. War is superior to peace (and even in RL it can be argued that most big empires did it through warfare). So there comes a point for every player, where they can handle more difficulty with war than they can with peace, when that happens depends on the player.
Now to your concern about science, its true the AI is getting better and better over time, and so your normal difficulty will get harder over time. For example I have been considering dropping back to Emperor myself, I was winning the vast majority on Immortal for a while, and was even winning a few Deity games every so often....but lately I'm getting crushed. the AI has just gotten too good, might be time to drop back. As long as the tier beneath me is competitive that's not an issue. So being an "Immortal-" player right now, I can definitely keep up with AIs on King and Emperor, so yes it can be done!
How do you do it? A few tricks:
- ETRs to the big civs. You should be milking lots and lots of science and culture yields from your opponents. I rarely use ITRs past the early game if I'm that far behind in tech, better to leach.
- Get Scholars in Residence and World Science Initiative (or the culture one can't think of the name right) passed. This will give underdogs a solid boost that will help you catch up.
- Spies: Level up spies in CS quests or diplomats, and then once leveled steal techs from your enemies. Obviously in the current version spying has been shaken up, so not sure where we will end up with that.
- Be patient: It does take a while to catch up to the AI but superior play will work eventually, but it will take a couple of eras.
If that is still not enough, enable Tech Trading. Tech Trading to me is a "peaceful civ boost", I mean sure warmongers can use it but a player with a strong economy can make lots of tech buys to help them catch up in tech. If you don't want to go down in difficulty this is a way to lower your current difficulty half way.