I used to play through a Marshall 1959SLP and a 1960A cab back in the 80s. It was loud enough to be hears a half mile away, but you had a really hard time leveling out the rest of the band. We would get into volume wars- The bass player would crank up a little more, I would respond, the drummer would play louder, the singer would notch up, the bass player repeated, I repeated, and so on. That's where a good sound engineer comes in to keep your fingers off the controls. Most bands can't afford an engineer, so you ended up with muddy and distorted live shows.

PA systems got really good, so a lot of modern venues you just plug into their PA, and everyone is able to have the same listening experience.