What’s left in regards to fitting an amp section with a driver ditto can as well be handled with the careful choice of an outboard approach, with even better amps and what fits a given listener’s preferences and specific acoustics to boot.
One issue is that all speakers (that I am aware of) designed to be driven with an off the shelf amplifier have a cross over that cannot be bypassed to directly connect to the driver. Hence any external amplifier is handicapped by the crossover.
Two would be the assumption the interface to the driver is a simple set of wires. Think of servo controlled subwoofers. They require a direct connection to a special amplifier that has additional feedback inputs. No simple external amplifier is going to work and the amplifier needs to be tuned to the speaker for best performance.
Three would be an assumption that a simple voltage driven external amplifier can achieve the best performance out of a driver, even if you were allowed direct connection to it.
Four would be the assumption that all drivers covering a similar function in a speaker are all going to do the same thing at the same time with the same frequency response. Even a one way speaker, can have multiple independent elements.
If your perception of an active speaker is just a passive speaker with a similar style amplifier in the box, with the crossover likely at the signal level instead of with big passive components at the speaker level, then making the assumption that a traditional speaker with an external amplifier can compete is a fair outcome.
The people working on the leading edge of active speakers are not making that assumption.
"Activeness" can be applied to any system just by the addition of the right processor like the new DEQX units or the Trinnov Amethyst. Then you have the ultimate control over what your system is doing.
You have full control over your system, but not over the drivers in the speaker.