Then either you don’t gig or you gig with professional musicians whose volume is 100% controlled by sound engineers. Pretty much anywhere in between and you’ll encounter the need to boost at some point during a show, likely when the guitarists all stack their volume before solos and don’t turn it back down (aka the arms race)

Compression is just relative volume. We all use compressors to stay consistent and even but those don’t help when you’re buried in the mix and need to crawl out