Old house, Copper wire but no ground
We have an older house that we moved into a few years ago. It has the older 2 conductor copper wire with no ground. Someone prior to us has replaced all the receptacles with grounded ones even though there is no ground. Also, there are numerous splices in the attic w/ electrical tape and no jboxes that I have been redoing w/ jboxes and wire nuts. I was at least going to rewire the bathrooms and the kitchen to add new 20 amp grounded circuits for those areas. Other than those rooms, does the whole house need to be rewired or is it ok the way it is since it is at least copper wire? Should I replace the grounded receptacles with ungrounded ones and use grounding adapters everywhere?