Are monoblocks better than stereo, with tube amps?

I prefer to run mono amps which allow me to run very short speaker cables with long interconnects. OTOH, I run everything balanced, so I can get away with that.

Like Unsound I also run longer speaker cables and prefer shorter interconnects. I am also a cj fan and that has also been their recommendation concerning their equipment.

The advantage of a rock steady power supply can be exaggerated. Let's say that the music momentarily requires a 40 volt level at the speaker. The amp's power supply is 80 volts nominal. No problem. Now suppose that due to prolonged high rms level signal the power supply "sags" to 70 volts. Can the required 40 volts be delivered? Sure. The transistors just turn on a bit more. In fact, 60 volts, or even 50, might be the nominal power supply voltage for a lower rated version of the amp that is perfectly capable of the 40 volt output.

Some amps are deliberately designed with a high voltage power supply lacking ability to maintain this voltage very long. This enables the amp to follow music signals much better than its continuous rms power rating would suggest.
That "rock steady" power supply is expensive, and so long as your signal is music it may be an unnecessary expense.

The more practical aspect which has yet to be mentioned is that monoblocks can get you the biggest dual-mono power supply (plus heatsinking capacity in traditional solid-state amps, or output transformers in traditional tube amps) without creating one inconveniently large and heavy chassis. Who really wants to contend with a 200lb. amplifier? Of course, you pay for those two chassis instead of one, and need two power cords. But with the new smaller switching-amp designs these issues can be finessed -- you can have a powerful stereo amp with dual-mono supplies without it getting too large or heavy, or you can have separate monoblocks for cable length flexibility without paying for (and needing to place) two full-size chassis. So I think it tends to break down this way: for high-powered tubes, monoblocks are typically the way to go, while lower-powered tubes can work well either way; for traditional solid-state either configuration can work well, with the ultimate high-powered edge going to monoblocks; for switching-amp solid-state, you pick it.