Galnet does it, wings do it, CQC technically does it, Powerplay does it...instantaneous comms cross galaxy exist...faster than light. FD hiding trade data in game is just a way to make an underdeveloped feature feel like a game. I'll say it again, even if you had to fly a fleet of sidewinders all around the bubble collecting market data by hand and voice comm it around, a corporation would make oodles of money doing so. Even if they had to write it all down by hand, take it all back to a central location, then redistribute it to every system, the data would be far less than a day old and you would make oodles upon oodles of money doing it. The system in the game is arbitrary and silly and a placeholder for an actual trade mechanic.
The system is neither arbitrary or silly. It is how the Elite Galaxy works: corporations jealousy guard trade data to artificially increase their profits, to the point of ordering assassination attempts on those who spread that information, and the four major powers in the galaxy (The Empire, the Federation, the Alliance, and the Pilot's Federation) aides and abets this strategy, because that is how many of their members make
their fortunes and remain in power.
Remember, an efficiently working economy is one where profits are slim, and people who make their living via profits will be required to actually
work for a living. Corporations and the Pilots Federation are organizations who make their living via profit. The current state of the galaxy is by design by the powers that be. The democratization of information is a direct threat to those profits, and the power such wealth brings.
THAT is the nature of the Elite Galaxy: a galaxy where corporations rule over most of humanity, who are kept ignorant of the
true value of their labor, and distracted from learning more by various forms of entertainment. A galaxy where these corporations outright buy representatives in Federation's parliment, are owned by the oligarchs of the Empire, and are member-states in the Alliance. A galaxy where these corporations ensure that the colonies they control are specialized to the point of being crippled without the imports those corporations bring in, making it harder for the people to revolt against their corporate overlords. A galaxy where these corporations don't want their competitors undercutting their carefully crafted monopolies.
And it's in the Pilot's Federation's best interest to maintain this status quo, because by maintaining the ignorance of the planetbound, we can earn hundreds of thousands of credits per hour, even in a small ship, as opposed to the meager 3 credits per hour earned by most of humanity.
The very heart of the problem, IMO, is that some of the "technologies" you mentioned above were tacked on very late in this game's development. There was to be no in-game FTL comms
by design. The wings update, and the comm channels it added, were a gameplay compromise that needed to be made, just like the "speed limit" in combat and the Frame-shift Drive, because in reality we are playing multi-player game, not a single-player game like past Elite. But just because some compromises needed to be made doesn't mean we have to throw away the very
heart of Elite, the thing that makes the Elite Universe different from other sci-fi universes.