Erm, you are using in the incorrect definition of "economy" in this context, which is disingenuous. The definition you cited is a synonym for "frugality" which is not at all what is being discussed. Since the definition used in this context is the very first one:
"the structure or conditions of
economic life in a country, area, or period also
: an economic system "
I can only assume you purposely avoided the salient definition to (poorly) make a point.
The economy *is* broken in the game. I believe the main issue is that instead of making unique items that feel different and like real upgrades, CDPR recycles about 25 different weapons in multiple tiers. So you have a (common) Lexington pistol that does 100dps and costs 400 eddies, and then you have the same (epic) Lexington that does 180dps and costs 40,000 eddies. There is literally NOTHING different about those two pistols other than the numbers attached to them.
Worse yet, you might spend that 40k for the Epic Lexington, and then ten levels later find yet another Lexington that is common yet does 210dps! WTF?!? So there are a million Lexingtons in the game that are mechanically identical, use the same ammo, and look identical, yet each one has vastly different stats and vastly different costs! So you end up with a case of "who gives a shit" every time you see a Lexington, and feeling ripped off an hour later if you ever buy one.
Wouldn't it be better if all Lexingtons did the same damage (modified by your skill in handguns), and if you wanted an upgrade you needed to find a new pistol? New models, animations, skins, more damage, and more expensive? Now it feels like you found or bought something interesting, that's not "just another Lexington", it's more meaningful. Maybe this one is worth 40k, because it's super cool and that's just what they cost, everywhere in Night City.
Of course, this would require CDPR to make more models, maybe 2-3 times the number now in the game. But upgrades would seem meaningful instead of just stat buffs. And don't even get me started on a Samurai T-shirt that can give 10 armor or 200 armor based on how "legendary" it is and what level you found/bought it.
--- PART 2 ---
Now consider why the economy and guns and armor are the way they are in the game. Ultimately it's not really a guns and armor and eddies problem, it boils down as so many other issues with the game do, to an AI problem.
When you encounter enemies, they have some level of badass-ery in relation to V. What does that mean? Well, now it's nothing more than the number of hit points, armor, and damage the enemy does, as well as the quality of loot they have. That's because the AI in the game is so weak, that is literally the only (terrible) way that CDPR can scale enemies.
So how else do you do it? With AI of course. Let tougher enemies have slightly more hit points, and maybe sometimes better gear. But in general, make them badass because they fight better. Right now all enemies fight as individuals, they just crouch behind cover or charge at you. That is lame behavior, and fine for low level gonks who just got their first Scav tattoo.
But higher level enemies should not just be (slightly) tougher, they should literally scare the shit out of the player with their coordinated tactics. Flanking, climbing to rooftops, feints where they pretend to run away but actually go around the block to attack from a different direction, all manner of behavior to make the player say "oh shit oh shit oh shit."
Now it doesn't matter that the higher level enemies "just" have a Lexington...because now they know how to use it, how to work together, and how to generally make V's life miserable and dangerous. Which is what Night City is supposed to be like. A skull icon should cause dread in the mind of the player. Not because it will take 50 bullets to the head to hill him, but instead because while he's moving around fast and effectively using cover so you can't even get a single head shot, his buddy is carefully moving round your flank to angle for a head shot on *you*.