I can't speak for all the games mentioned and I'll grant you WC/Privateer, but the X-Wing series (particularly from TIE Fighter onwards) has the player taking part in dogfighting, intercepting, disabling, scanning, escorting, capital ships attacks, with ships constantly getting in/out of the combat zone, a massive variety of ships of all sizes, some of them capable of launching waves of fighters/bombers, changing objectives, wingmen, allies, objective-driven AI... By comparison, ED combat consists in dropping out at a location and killing the random single pilot ships that keep spawning forever, with the AI simply aiming to destroy whichever ship it perceives as the biggest threat. I guess Thargoids can be considered as a first actual capship run mission type.
Yes, ED has more gameplay options than the X-Wing series for example, but they are most definitely basic compared to what other games offer/have offered before. X-Wing only does combat, nothing else. But it does it incredibly well despite a very simplistic flight and weapon model. And that's combat, which imho is the most fleshed out feature of ED. There is still a lot that can be done to make it a deeper and more engaging activity. Taking some of your other examples, FSX and DCS have very deep flight mechanics and instrument simulation, and make it available to the player as a sandbox to experiment with. Another case of doing less things than ED but doing them in much richer fashion. In fact, you might have noticed that FD are dedicating the entire Beyond series of updates to improving the current gameplay options. It's not because they're already state of the art, it's because they're not up to scratch yet, but may get there given time and resources. It's not a slur on ED to admit that the current gameplay is rather basic. It is what it is, and it allowed FD to provide a breadth of activities. I, for one, am glad mining and driving on planetary surfaces is available, even as shallow as it is, because that's stuff I enjoy doing. Had the time and resources been spent on better combat experience, I don't think I'd enjoy it as much.
And at any rate, deep gameplay is not necessarily fundamental. ETS2 is absolutely mesmerising for many people, myself included, and its gameplay is incredibly basic. It is, however, incredibly engaging, a quality that I also associate with ED. And a quality that imho SC will certainly have. But not everyone values evasion as much as me, and I most certainly can see why one would rate ED badly based on gameplay alone. It is not nonsense, ignorance or misunderstanding space sims, it is a question of valuing different things. And it most certainly isn't ridiculous.