Non grounded outlets

I do a lot of home inspections in older homes that have non grounded outlets but are three prong outlets. Is it required that they be grounded since they are three prong, or recommended that they be changed to two prong?..I guess what i’m saying is that in either case it will not be grounded. Or is the best recommendation to recommend an electrician add a grounding system through out the house.

What is the wiring method feeding the receptacles?

Report what you find .
Ungrounded U ground outlets need to be repaired by an electrician immediately . Move on .

Ungrounded three prong receptacles are allowed under the NEC if GFI protected. There is no need for repair. The CEC may be different.