Do you mean to say that in real life, a response of “traffic in sight” can legitimately mean “I cannot see the traffic and never will be able to see it at the angle it’s at”, and that a response of “traffic not in sight” would always be followed up by a second request to look for the traffic, third request, ad infinitum?
(I think you mean more like that if you respond with “traffic in sight” you’re confirming to ATC that you’re responsible for separation, while if you say “traffic not in sight” you cannot do that, so ATC is still responsible? And thus it may be legit for them to keep asking you every several seconds in case you can see them now?)