Actually for the Moto Z phones at least the 1st gen ones it seems to be pretty common. The Lenovo forums are full of people with the battery issues. Some suspect it is a software issue as new batteries have been reported to only last about a month or so before they also die. The Verizon store I visited also said they were aware of the issue. However, Lenovo won't acknowledge it.
The not liking apple thing comes from professional experience with them in supporting their desktops and their rack mount servers they had years ago. Dell always treated us much better than Apple did when we had a hardware issue. So, it is not really a "fangirl" thing. Not to mention he wouldn't like having to re-buy his apps on iOS. We have already bought into the android ecosystem.
I agree there don't seem to be a lot of cheaper options. It seems Moto has that market to itself on Verizon. I have switched form Verizon twice and always game back due to service. Not for price though as Verizon isn't cheap. But, the other services (AT&T, Straight Talk) I have tried didn't work as good.
I will show him the Pixel XL, Moto G6, G7 Power, and the Z3 and see what he thinks. I am leaning toward the G7 Power. Being new it should get updates for 2-3 years and it is focused on battery life which is what he needs as he is always on it, like most kids. And, except for the Moto Z's Moto has always made a good phone.