VU Meters were all the rage in the 60’s and 70’s… McIntosh being one prominent adherent well into today. Big reason why they were dropped was because a lot of people noticed they were not using that much power to “swing the needles”
So trying to sell a triple digit amp when people were armed with knowledge didn’t seem like the path capitalists wanted to take. Some manufacturers even build power hungry speakers just to sell their big watt amps… see above for example.
The total power of a amplifier should be taken with the knowledge that you should have enough headroom for dynamic passages. Lots of amps will run in pure class a for the first few watts. You also should take into account the load the speakers present. Inefficiencies will require power. For example, you could run a pair of very efficient horn speakers, like Klipsch with a modest few watt tube amp and enjoy satisfying volume.
