It's not even true signal strength. Certainly on 2G (I'd have to double check on later technologies) the radio can inform the UE to treat the recieved signal level as being an arbitrary amount better than actually measured.
This applies to signal level as reported to the user as well as internal metrics, eg handover (is this other cell better, should I switch to it?).
And with 5G we are dealing with so many frequency bands, users and so on that the strength of signal really tells little.