Is there any obvious advantage for monoblocks?

Subaruguru...We agree! (Something must be wrong here). All my power amps and electronic crossovers live in the cellar, and have done so for decades. Besides, that way you can hide from your audiophile buddies the fact that your amps don't carry high end nameplates.

High power capability, that you can still pick up and carry.
Short speaker wires/long interconnects... probably a wash.
Separation (low crosstalk) is a myth unless your stereo amp is a clunker.