@phusis , I can only speak for myself, the reason I don’t use an outboard amp configuration and active crossovers is space consideration. For a two channel system NP, but when you have a HT with 5,7, or more channels it would be a monster to have to store all of the additional gear. Internal amps is the opposite, takes away the racks I need and gives me biamped speakers for less money than I could build myself. No doubt, it could be better and I know you can use the Storm Audio/Bryston SP4 HT processor DSP capability to run active crossovers for each channel but you still need to house all the amps somewhere.
Theortically you could do this if you got the Bryston SP4 processor and then 5+ of the Bryston active speakers but it would be complex and you still need to house all the amps.
https://bryston.com/preamps/sp4/