We're discussing multiple topics:

What power do the speakers need? It DOES depend on room size and on how loudly the listener wants to go. Big room OR more loudness = RAPIDLY increasing power demands.

What power do multi-channel amps need? In addition to the consideration above, it also depends on the type of demand placed on the actual speakers by the soundtrack. With all speakers set to "small," and a self-powered sub in the room, no - you don't need much power per channel. After all - Only the center and subs have any work to do - everything else is effects.

But for stereo-only listening (assuming a two channel amplifier) and with NO subs, then things become more demanding for the amplifier. If the speaker has a complicated & lossy crossover (think Thiel) then the amp must be more robust. If the speaker has low impedance (particularly over a broad section of the audible frequencies), then the amp must also be more robust.

Any stereo amp that can't double its wattage into half the impedance is limited by its power supply. For most speakers, and at lower volumes, this isn't an issue. In fact, Axiom speakers seem to have a benign impedance curve (rarely below 4 ohms and only for limited frequency ranges). But despite claims to the contrary, an amp that CAN double its output at half the measured impedance is an amp that is NOT limited by its power supply.

Note that this says NOTHING about how the amp sounds! Lots of "pro" amps can double their wattage into half the impedance, but they sound grainy, bright, and just plain ugly.

Best, to my mind and specifically for stereo listening, is to have a mono or stereo amp that has a muscular power supply.

Such an amp is gross overkill for multi-channel listening (which is why AVRs lack the capability - even on flagship models). Different purposes - different designs.

I don't put the Axiom amps down for not providing that much current for multi-channel designs - it isn't needed. I also note that the two-channel Axiom amp DOES double its wattage from 8 to 4 ohms.

Boom

My opinion is worth exactly what you're paying for it!