Are they? I've had excellent success. The confusing part of this is that there are two types of PDF. The first is a "normal" digital PDF. The second is a
scanned PDF. The first can essentially be read like a document. LLMs have no issues with this. It's the second kind of PDF where the constraint becomes the vision capability, and this is very impressive with Astra. I've had no issues with either. I imagine there could be issues with unusually dense and/or misaligned text on scanned PDFs, but I have not tested this.
The bottom line, though, is that PDF OCR is usually regarded as a solved problem. LLMs won't usually do the recognition itself. It will farm it out to established tools which are very good.