It depends whether you’re talking about active or passive bi-amping or tri-amping.
Naim have in the past famously championed active bi-amping and active tri-amping, however, this does require specific speakers and, with Naim’s own speakers long discontinued, there are few options for this these days and it was always a pretty small and niche market anyway, with plenty of resistance against the complexity and capricious nature of such systems.
As for passive bi-amping (or tri-amping), Naim have generally felt it to be a bit of a waste; Instead of buying two lesser power amps, better to buy one better power amp for similar money - you generally get a better performance result. Of course, there are exceptions to every rule, and certain speakers which were always designed for multiple passive amplification (e.g B&W Nautilus), or in the case of 2 x NAP300 vs. 1 x NAP500, the former might well be a better bet than the latter with certain hard to drive speakers.