I always charge it while I sleep. It makes obvious sense.
So if I use my phone during the day, on average I’m between 60 and 80 percent charged at night.
So I can leave it unplugged and start my next day with whatever is left after further discharge through the night, because I’m always getting messages that I check first thing in the morning (I usually leave it plugged in while I read the messages, respond, and until I get out of bed).
So starting my day with whatever is left from the night and prior days use isn’t ideal. Because I do have days where I am heavily using the phone and could be at 50% by noon from a full charge. If I started the day with 60%, and I’m down to 10% by noon, I have a long way to go until 1:00 am when my day tends to end. 10% isn’t going to get me another 13 hours.
And yes, my typical day is 8:00 am until 1:00 am the next morning (frequently ending between 3 am and 4 am). Fortunately, I get more sleep than I used to. I used to end my day at 7:00 am and start again at 8:00 am. I lived that way for 10 years, every day.