When I hear the vast majority of fingerstyle guitarists playing steel-string acoustic guitar - i.e. not plugged in, I am invariably disappointed with their lack on volume. I bet I would even be disappointed with Ry Cooder's volume - or lack of it! A plectrum solves the volume problem. Nowadays, I do a lot of "hybrid" picking ( with pick and fingerpic(s) which can - a lot of the time - give the best of both worlds. Too get a really good acoustic sound, playing fingerstyle, I think you're talking false nails etc. Martin Simpson used to get a fantastic loud acoustic sound.