There's nothing magical about the Evo or how it makes power. Mitsubishi gave it a large turbo (compared to its displacement) while Subaru has always been stingy with the snail.
Mitsubishi gave the Evo a real FMIC, not the top mount bbq grill that Subies get stuck with. It's got a robust fuel setup too, that isn't out of capacity until the turbo is too.
To top it all off, the parts to make your Subaru equal are subject to the Subaru Owner's Tax, by which everything is marked up 200% over what it should be worth.
I wouldn't try to run 30 psi on the stock engine like Evo owners do, but then again, I won't ever have to. I'll be quite happy in the 21-22 psi range when mods are complete.
People were jealous of the Supra because all it needs is a downpipe & MBC to hit 117+ mph traps. Again - it's a case of having the right components from the factory vs. having to add them yourself.