One of my longstanding complaints about the entire illusionist archetype comes down to, "why are you wasting time creating pretend spells when real spells exist" and "if it's possible to conjure a horde of pixies out of thin air with one spell, why would anyone disbelieve you creating an illusion of a pixie horde?" (and yet, the NPC's seem to do it every time, lol). Even other game designers have noted this, AD&D Illusionists eventually learned real spells at their top spell levels so they had some real magic to use in case everyone figured out they were an illusionist and disbelieved everything, and the Earthdawn Illusionist similarly had a few spells with real effects to mess with people who had a similar thought process.
I mean, sure, in theory, you could fool people by disguising low level illusion spells as higher level real spells, but I've never seen that work out well in live play, only in stories about awesome illusionist characters, lol.