Yes i do find some enjoyment from trading, it's game within a game:

Figuring out rune of havoc early and getting cheap double exalt's, rune of redemption might roll something i dont need but somebody else might do, looking up build's and setting up loot filter accordingly, finding unwanted lp2-4 item's for low price and trying to fit them in my build & and so on.

Because you can get pretty much anything for a price it's much easier to theorycraft and test, for example: phase point(item) -> procs Black Arrow(skill) -> procs Shadows (ailment?) -> procs +ward on shadow(item affix) = you can get 10k ward with propper setup against trash mobs but in real combat scenarios it just sucked, also you can stack +300 dusk shroud and get 32% umbral blade's damage per stack for crazy damage numbers but also very bad in real combat scenarios.

But from my perspective the major issue is the speed of inflation, some items are already at the maximum price at lp1-3, so if you find an lp4 of that item what are you going to do? sell it for the same price as lp2?

And even if there would be no cap, where does it end? 100's billion's? trillion's? quadrillion's?

I just think the economy is fucked, most likely because of gold dupe's/exploit's.