I wouldn't just write one off over the other, both are useful in their own ways, you just have to approach it on a game by game thing, one thing I would say is never not use any of them, it is quite shocking how dim the highlights are when you just use off, almost SDR level.
It mostly depends on the game tone mapping and in-game sliders/controls.
Even with DTM and HGIG both Off, games with proper 4.000 nits Peak HDR Luminance and decent Paper White (around 200 nits, similar to movies) will look perfectly bright and correct.
For those games with no in-game HDR controls at all which often internally target 10.000 nits and/or with low default paper white will look awful without DTM etc.
HGIG is usually the most accurate setting with proper in-game HDR sliders (just set those to 800 nits and there's no tone mapping at all: what the game will output is what the TV can actually handle and that's it), but sometimes even in those cases final results may be too dim for many as the "HDR effect" may be only enjoyable in totally pitch black rooms.
For these reasons there's no clear winner as you stated:
DTM should be more consistent/pleasant across the board, but less accurate.
HGIG the most accurate, but often too dim.
DTM/HGIG Off (or just with regular Dynamic Contrast: Low) is perfectly fine for 95% of Movies and all Games which can actually go to 4.000 nits, but can also be too dim in more generic HDR games and those 5% of Movies which target 10.000 nits instead.