It takes a little bit of reverse-thinking for players used to Revised and reading M20, but not needing Quintessence is *why it's not mentioned* under the Prime 2/Conjuration in the M20 corebook.
Or put differently: If you put a new player in front of a M20 book, and they read up on conjuration, they'd not even get the idea that Quintessence is needed for it. And that's how it's intended.
You do however, as also mentioned in there, need Quintessence if you want Forces to persist after the first turn if there is no fuel for them. Say, a fire. So, hovering a fireball in mid-air for a few turns, or setting stone on fire for a prolonged period, needs Quintessence. Setting hay on fire does not.
And while you can of course just spend a pile of successes on making it *effectively* permanent, give that an item lasting years and years is probably enough in most cases, the key difference is that such an item can still be removed by unweaving the effect.
I treat the added Quintessence as making the item a permanent, vanilla part of reality.