Single way or multiway

The issue with single driver speakers is covering  the entire freq spectrum humans are capable of hearing. I've owned Omega and Jordan single drivers, both were unsatisfactory in this regard. I suppose one could add subs and super tweeters, but I'd expect major problems with integrating them, and you've lost the principle of simplicity. 

I suppose most don't fret about their passive crossovers since the loudspeakers they've chosen provide contentment. The importance of knowing the specs of one's speakers and providing sympathetic amplification mitigates most issues. I've not seen empirical evidence that provides universal superiority of minimalist passive or active crossovers vs more complex crossovers. Speaker designers  are pretty sophisticated these days, have many drivers, crossover components to choose from, based on listeners experience I trust they know what they're doing. If what you propose is clearly superior don't you think they'd go down this path?