I've been doing not much for a while now. But we were playing, I would have killed you in the first 10 years or so when I had the 4th level of red laser and the 4th level of spaceport and everyone else was still using what they started with.
Have you played on insane? The AI gets double all productions, including research and also double fleet capacity. I'm already fighting against a tech curve. A guy with only one planet is just food.
I'm not saying it can't be beaten, but it's pretty scary because I could just make a ton of colony ships and then build the basic spaceports if I wanted to, it's not like all the overpowered research will be taken away after. All you really need is fleet support.
Not quite true. You need the fleet capacity, sure. But you also need all the energy and minerals from planets to support that fleet. You'd break your energy credits if you ever tried the rapid expansion you describe, and you'd never be able to do it during a war.
I'm losing energy because I have about 15x 4.4k forts out there and they have serious stacking upgrades already. I would not be surprised if one of them could solo that entire 10k fleet of yours.
Let's see, your screenshot shows 4 systems with military bases. Let's assume they each have 4 in a death blossom configuration. In 40 years, when my fleet is at least 4x the size it is now, your forts wouldn't stand a chance, just as your fleet doesn't. And if your fleet can't leave spaceport in fear of losing it, I just blow up one spaceport and contain you while I research your techs.
Now, I understand the point you are making.
If you can stay as a single planet, do so for as long as you can. But eventually (and quickly on harder difficulties) you need to expand, and fast. Otherwise, you'll just get rolled over, tech advantage or no. I challenge you to play on Insane with your strategy. Give it a shot. Let me know your success rate.
If you can't beat Insane AI, how do you expect to beat people who reliably can beat Insane AI? If you can't beat a Fallen Empire by 2300, or survive against a crisis, your build has failed.
EDIT: What if I just picked off all your mining bases, especially all the power producers? You can't defend your space with your fleet for risk of losing it - once gone, it'd take years to reproduce. Eventually, you will starve out.