My problem with the Game Mode is not that it's bad, I prefer detail to brightness, it's that it COULD keep overall brightness AND keep details, if LG decided to use the same PQ EOTF curve as Panasonic, that tries to follow the intended brightness until around 300 nits and then starts to move away from it, instead of doing it from the start. The result is that darker parts and mid-tones would be brighter, while the brightest parts would be compressed but still show detail.
The sad thing is - LG did decide to do that - on the 2018 models. Ok, so we don't get Dynamic Tone Mapping in Game Mode - fine. The sad thing is, on 2018 sets you don't even need Dynamic Tone Mapping in Game Mode (but you have that option if you want it even brighter). I'm not an engineer, but I really don't think there is anything stopping LG from implementing a different curve on 2017 sets, like they did on 2018 ones.
LG is definitely improving the Game Mode, the problem is they are doing it with each new generation, even for things that could be done on older sets too. And with people not understanding the problem, or not caring, or asking for something that LG won't (and frankly, shouldn't) do - like bringing back the "old" Game Mode - I don't think there will ever be enough pressure for them to change anything.
A new EOFT curve would be great - and they already did it with new models. If I was cynical, I would say it's because they want new models to look better. If I was a pessimist, I would say that it's because they don't care enough to dedicate resources to change anything. An optimist would say they will get around to it, eventually.
Still, even with all that said - the HDR mode is not "dim", it's just not as good as it could be. On some games, like God of War or Assassin's Creed Origins, a few in-game sliders can almost negate the issue. But you do have to fiddle with the options and use Dynamic Contrast which some people dislike (I think Medium is great for GoW or AC, while High is great for Uncharted).
My real problem is that I just can't notice the difference in input lag when using Cinema Mode (with Active HDR on - DC Low) but I keep thinking about it and blaming lag for every wrong move, so I am going crazy switching from one to another. Got my C7 for a good deal but I keep wishing I spent 500e more for a C8. It is still insanely better than any other TV I've seen, even in Game Mode - but I keep changing settings and tweaking instead of, you know, playing games. Perhaps I should just deal with it and accept that something better is always around the corner. I can imagine C9 will make HDR even better.