Being that no amplifier is load impervious its performance will always be contingent on which speakers it's mated with (and vice versa), which is mostly about the obstacle that is the passive crossover situated between the amp and drivers and which severely impacts the interfacing between them. To make matters worse: passively one amp channel drives the entire frequency range of a speaker, and thus the higher frequency bands are affected by the power requirements down low, which has sonic implications - not least at elevated SPL's with complex and LF-heavy music material.
Once you remove the passive crossover between the amp and drivers for direct and dedicated amp channel connection to each respective driver section actively (out- or inboard) - the passive XO replaced with a high quality DSP/electronic crossover - you significantly lessen the load strain presented to each amp channel, which in turn means making more effective use of its inherent performance envelope with a more effortless and lower distortion sound to follow.
With the better interfacing between amps and drivers/speakers actively one is to roam more freely in the choice of amp not only from a power and overall matching perspective, but also with regard to much more easily harnessing the fuller performance potential of an amplifier. This way a higher performance will be achieved vs. a passively configured scenario with the same amp, although one will need more of them actively and as many that are required to cover the driver sections.
It would seem stupid (and yet for the industry self-serving, certainly economically) to produce massively overbuilt and astronomically priced amps weighing in at hundreds of pounds as a (partial) answer to inefficient, load-heavy high-end speakers with power sucking complex passive crossovers, when you could let go of such a system's severe bottleneck and be good, indeed better with much cheaper amps in an active context.