I still have my Quarks, great little lights! Like you, I also greatly prefer my lights "shit simple" and truly have zero desire for the vast majority of multifunction lights that have flooded the market.
Assuming we are speaking of lights small enough to comfortably carry in the bottom of a pants pocket intended for general utilitarian/administrative use, I have settled on a simple, single-output light. The key to my 100% happiness with the single output was finding the right amount of lumens and overall beam pattern. The light that I now EDC for this purpose is a Malkoff using their 200-lumen M61L drop-in, which I find bright enough for outdoor navigation but not overwhelming when looking for something in a box or under a chair. I've found that I more prefer the simple, rock-solid operation of this light than having a second lower output.
Dead-nuts simple, built like a brick poop house and utterly reliable, with about two hours of runtime on a single rechargeable 16340 Li-ion cell. To me, that defines the light I want with me at all times.
Malkoff VME head
Malkoff M61L drop-in
Malkoff 1CR123 body