Steem powered up is for long term investors. Liquid steem is for on-ramp and on-ramp purposes for those investors, as well as traders and short-term speculators who want to play it that way. SBD is for everyone else, ideally. Unfortunately, as I commented in a reply to you elsewhere, there isn't any way to separate the long-term investment component from the social media component, so for someone who just wants to be a long term investor (not social media), no ideal vehicle for that currently exists.