Too few resources to corrupt a spell gem

I have 690 hours in PoE2 and haven't successfully corrupted a single spell gem to get +1 level. So far I got -1 twice, loss of sockets, and other "dud" outcomes even when using the Omen that forces a change when a Vaal Orb is used.

In the case of Essence Drain, you need to corrupt a 5-socket, 20 quality gem, in hopes to get +1 level. Perfect Jeweler's Obrs are few and far between and they are the rate determining part. Each time one drops, I craft the spell, quality, socket and then Vaal.

Maybe this is the "intended" pace but it seems a bit too unrewarding for my taste.