I think most you (even the ones defending 2d20's "Meta-Game" mechanics) are missing the point behind those mechanics.
I think over the years, especially recently from D&D play-test surverys, is that Story-telling and Roleplaying are at heart of an RPG.
Some aspects of the "Meta-Game" mechanics of the 2d20 system are aimed specifically at enhancing Story-telling. Such as troop reinforcements and environmental effects.
For Mutant Chronicles (the original 2d20 system game) the mechanic is called Dark Symmetry. And frankly the game just wouldn't function well without it, because the Dark Symmetry is so interwoven into the Setting. If fact the characters are supposed to understand the presence of Dark Symmetry almost as something tangible. Its necessary to feel that impending doom always pervading among them.
In Conan, they just re-worded it to "Doom".
Where I believe Modiphius went wrong is they should have re-hired Jay Little, gone back to the drawing books and the designed a system from the ground up aimed specifically at Sword & Sorcery. So their "meta-game" mechanic should of been aimed at making Combat more visceral, brutal and cinematic. I think that would of had a better effect. Because when reading Conan, I don't get this pervading doom feeling on the horizon, but I do get the sense of brutality, a gritty dangerous feeling that you are on your own and nobody is going to save you.
Impending doom and the ultimate pointlessness of the effort to carve out civilisation from barbarism, honour from savagery and compassion from a pitiless cosmos are at the very heart of Conan - the Conan set in the middle of the Cthulhu Mythos, the one where the most awful sorceries and inhuman monstrosities exist alongside human decadence, pettiness and cruelty.
I think you may have missed that...
The reason you may not see it in the Conan stories is that Conan is such an exception to the rule. Perhaps you need to pay more attention to the rest of the characters - how quickly they die, get corrupted, betray, even when they were decent to some extent at the start. Those that don't fall get killed, frequently - just look at the sailors who save Conan only to die under Belit's crew's blades, leaving only Conan standing. Look at how many times Conan is helpless, only to call upon amazing inner resources to turn the tables on long odds, and how many times even when that isn't enough, fate intervenes and he is saved by circumstances or third parties.
These things in juxtaposition are actually surprisingly well served by the Doom and Fortune mechanics - and saying that Doom points doesn't facilitate visceral combat is the exact opposite of the experience me and my players have every week when I run it - so I can only conclude you haven't run it or played in it.
It is however true that reading it without playing it concerned me in a similar vein to you, and only playing demonstrated to me that I had been worried about nothing.
I don't like FATE because of it's metagamey feel, and I don't like the idea of such mechanics in general, but I like Conan and it's mechanics.
They are not mechanics that are easy to make accurate presumptions about - they need to be run with before forming an opinion. In a way that is sad, because too many will not try it because of this presumption.
That said - I don't think it will work for the upbeat cosmos of Star Trek - it is key to a 'doomed' and dark gameworld, not an episodic science fiction morality play in the style of Star Trek (which I love btw...).
So please understand, I get your point - I just think you've made it with entirely the wrong 2d20 genre.