you can get 3-metre thunderbolt cables if you want, you just have to pay a lot for them. all the problems with USB-C can be solved by spending more money. if you want to go the cheap route and buy cables that don't support all the various modes, then you're going to end up with a bunch of cables that don't support some modes and have to keep track of which ones those are.
if you regularly use devices that need higher-spec cables, it's probably worth keeping one good high-spec USB-C cable in your bag, instead of three terrible ones.
I guess it's cheaper now but in what world is a $50 cable to power an accessory reasonable in any way.
Source: https://www.sweetwater.com/c1225--Thunderbolt_Cables
It carries probably 100W+ for power, multiple 4K displays, ethernet, half a dozen USB3 ports... I'd rather it not be the thickness of a 5W charging cable.