Seems that trading must be fixed, it's not profitable if you're trading on your own without doing missions.
If you don't care about hurting your rep or making the pirates/LP strong then dealing Drugs/weapons/organs/troops is insanely profitable.
It's not insanely profitable, since i can't even fill my cargo with these stuff and most of markets have around -200 deficit.
Trading not being profitable later game isn't the same as early game. I mean you could turn 30,000 into 1.5 million in about 1 hour doing these kind of trades using several Hounds. Tariffs and the way commodities scale based on number of units is basically broken and gets worse the more cargo you can carry. Small ships (less cost) and limited high end cargo works, run D mods and skill for lower maintenance. If you wanted to make millions per trip then no, not insanely profitable. But if you stay small you can make insane profit, insane relative to your expenses. Everything is relative. Profit being double your costs per trip in insane, you not being able to do that with all your cash every time is another issue entirely.
As far as end game and Super freighters there is no profit to be had. 1000 of anything being sold in any one place is enough to make the product worth less then the original cost, let alone the possibility that you could haul 10,000 cargo.
That's the problem, you don't want to make 1 hour of trips with ilegal cargo, losing rep to make a million, because you didnt spend this time doing bounties or exploration. It's more harder than everything else. Traders have no place in game on their own, just with missions (if you can get one)
I've never personally experienced losing so much rep to make a million, nor have I experienced exploration being faster money than the shortage trading. Even when I got caught smuggling, the only real loss was -5 relations. That relation loss is easily repaired the moment a faction posts a system bounty and I went in and cashed it in.
And trading really is considerably more profitable than exploration if you are exclusively shortage trading. A single trip for 200-300 drugs or weapons nets 100k+ in profit and takes mere minutes to complete, without needing to use up supplies flying out inner core. That said, to reliably trade on shortages, you either need to pay close attention or you will need to be the one that creates the shortage (which is easy enough to do by killing a smuggler).
And before you point out how killing smugglers reduces relations with independents, consider what you actually get from being friendly with independents. The answer is absolutely nothing, except for two awful military markets that you shouldn't care about. As long as you run transponder off, independents will never bother you, ever.
If i'm not wrong, attacking Remnants now you get a chance to find a Alpha Core, having the certain perks makes exploring is ALOT more profitable and you can earn around 500k nearing 1m per trip just exploring and getting these stuffs and selling for who pays more with that bonuses of rep and bounty at 200%-300%.
Supply Shortage of course give a nice sum of money, but you must pay attention on invasions and stuff to do this trading right, and ofc... You have a risk, you get that amount of goods and then the market just stabilizes and you lose all your profit.
I mean, really, trading needs a rework and be more "inviting".