This question is valid for both mechanical and hydraulic brake systems.
- The human hand has a threshold value for what a comfortable level of squeezing force is, and one cannot comfortably reach this threshold repeatedly. (See Chris' excellent comment below.)
- The brake system is not externally powered.
- The usual laws of physics are being obeyed.
I am not understanding how some brakes can be unequivocally better than others. One always needs to balance power, lever force, lever freestroke, and pad clearance.
Fundamentally, brakes can be modeled as a simple lever. One causes a relatively large but weak movement at the lever, which triggers a small but forceful movement at the caliper. Hence, more brake power almost certainly is at the expense of caliper movement (which allows for some level of rotor/rim runout to avoid rubbing). A brake setup with larger pad clearances is either going to be weak, or have large lever throw. There's no free lunch.
For instance, the Shimano Saint and Zee downhill-oriented hydraulic brakes use a greater leverage ratio in the levers to create more power (which could be defined as the clamping force). The tradeoff for this reduced proportion of pad movement is their noticeably longer freestroke, i.e. how far one must pull the lever until the brake engages. Conversely, most SRAM hydraulic brakes use a "normal" freestroke and a generous pad clearance, which results in their characteristically mild power.
Of course, there are many factors involved, such as dual-pivot rim brakes, Shimano's "Servo-Wave" and SRAM's "Swinglink" variable-leverage designs, pivot bearings, two- versus four-piston hydraulic calipers, or even plain old manufacturing quality. These help overall, but on a level playing field where every brake incorporates some of these features, I don't see how any one brand's implementation clearly outshines the rest.
I suppose the root question I have is "How can $900 Trickstuff (or other premium manufacturer's) brakes be worth that price when they have to balance the exact same physical factors as $200 brakes from Shimano et al?" The high-end brakes are reportedly better than cheaper ones in every way, but I am not seeing how that is possible when considering the inverse relationships between many of these criteria.