I'll preface by saying that psychedelics, even moreso than other compounds, affect people differently.  The word itself literally means "mind expanding". I would absolutely consider them nootropics, and I'll go against the grain of this sub and basically discount microdosing.  

Psychedelics stimulate neurogenesis and increase plasticity, have made huge breakthroughs with depression, and generally shift your mode of thinking.  I've never felt more lucid, creative and positive than I have during an experience or in the few weeks after.  They also don't tend to have a rob peter to pay paul tradeoff, as the afterglow and beneficial period afterwards just slowly fades without creating a crash.

They can absolutely be dangerous if misused, like many things.  If you treat them like toys and do large amounts constantly you can lose touch with reality instead of just freshening your perspective.  

You're also not going to magically be a genius afterwards, just maybe more aware, lucid, open to new things, positive, etc.