I've always wondered why line combat was used during the 18th century because it doesn't seem very effective, while it has some merit in usual warfare it just seems like unconventional warfare would probably win in all engagements against line combat.

I can see that it might be a defense against cavalry but it still doesn't seem like the best possible Choice.

Of course i don't know much about the 18th century or combat tactics of the 18th century, so i might have missed some important details.