What does it matter what his current screen time is? Two people just told you they get 5 hours of constant screen time and 3 hours would be a bare min with hard hard gaming and tasks. For what this phone is, it does fantastic for its battery.
And if you are spending 5 hours staring at your phone you may just be an inrovert. Lets think about this, if you spend 5 hours glued to your phone, thats 20% of your day blocking off everything around you. Thats alot of things to miss out on.