I think that megawatt power amps were necessary if you could afford them + you had a big enough room for them to perform to their max to create outdoor concert-level SPLs.
I seem to also think that megawatt power amps are dwindling due to the economy. These amps require huge power transformers & just the weight of these power xformers necessitates the use of thick metal for the chassis & huge heatsinks. That's a lot of machined metal that costs a pretty penny. Many people are not going to spend that kind of money anymore given the way the economy turned in 2008.
I seem to also think that megawatt power amps are dwindling due to the economy. These amps require huge power transformers & just the weight of these power xformers necessitates the use of thick metal for the chassis & huge heatsinks. That's a lot of machined metal that costs a pretty penny. Many people are not going to spend that kind of money anymore given the way the economy turned in 2008.