As you can probably guess, there’s a more accurate means to determine your strength of your phone’s cellular radio than that icon in your status bar. On Android you can find numerical values, measured in dBM and asu as in the grabbed screen above, by navigating through your phone as follows:
Settings > About phone > Status > SIM status
While you could make the argument that Google is already doing a pretty good job of hiding this information from the user, a curious new commit to Android P discovered by XDA would suggest that it could be removed altogether. The reason for doing so can be found in a comment on the commit:
Hide signal strength when told by carrier
Ok Google, you suck.
At best, carriers might simply wish for their Android offerings to be less geeky and intimidating for new users; at worse they don’t want any attention drawn to their sub-par networks. For me, it’s yet another reason to steer well clear of carrier-branded hardware.