Proactive offensive charging is both better for the phone and lessens the benefit of the phone, relative to reactive defensive charging.
Proactive charging is when you take every opportunity to keep the phone charged, so its charge below 100% is really how long the phone spends in your pocket. Phones are mostly about pockets and hands. If the phone spent a long time at 100% its not really a phone but its been used as a tablets.
If you gather together your proactive system which is chargers all over the place then your phone battery will last longer elapsed time and you’re going to be with a phone about to go off from flat extremely rarely, it would be when you’re basically spending all day outdoors away from anything other than your pockets.
Most phones struggle eventually after 2 years and so need the above more often, i.e. the number of days your phone turns off due to flat moves from never to rare to often which is after YYY days. Then you can either crack open the phone and follow a guide to replace or buy new phone.
I am struggling to think of a time my phone has gone flat…
Reactive charging is when you basically think “it is a phone! Freedom! No caring about any kind of plugging in for all days for XXX days” But then XXX is less than YYY.
Eventually your old phone for battery or other reasons is no longer worthwhile for you, then it becomes a spare backup phone, store it about 70% charged and every few months recharge it and discharge it and store it again at 70%. Those phones in my experience still function as a backup til about 7 years old then the lithium battery has oxidised so much it is cracking open the phone case and is dangerous.