iphone 15 pro max not charging properly

so I upgraded my contract around 5/6 months ago and i can say that the 15 pro max is one of the worst phones I have owned constant issues being not booting up, not charging, charging slow with a speed cable ect. to charge my phone I have to do a reboot on the phone (volume up, volume down, power button) for it to even charge and sometimes that doesn't work so I just have to let the phone die and hope for the best, Why are we paying an absurd amount for a phone when the company that makes them doesn't care about the customer