Yes.....exactly.....downhill requires no gears, so 12 is too many!1× has possibly replaced 3× because 3× offers an unnecessary number of gear ratios for the kind of terrain ridden on an mtb.
Sadly 99% of downhill drivetrains don't get used downhill....they get used like every other bike....for lots of stuff .
Big Jumps between cogs downhill is fine, but on the road makes for an annoying and uncomfortable ride. Its the equivalent of say just use top middle and bottom on a 7 speed block due to the massive spacing gaps. So either pedal like mad or push your guts out.....sorry not for me......i will stick with the "non comsumer" option.....no thanks mr shimano.....but do enjoy your share dividend off the drones money.