Yeah, absolutely. I live about 4h south of Orly and 5h south of CDG, and would have to backtrack to Lyon to take one of the few TGVs per day to CDG. There’s no option for ORY that isn’t changing in central Paris.

PS: How long would it take you to get to CDG if you would change in Paris to the RER? But you would have to change twice, no?

Yes, train connections from regional towns to other regional towns in France are complicated it to put it mildly.