Slow charging or a battery that drains fast is usually an accessory problem, not the phone. Here's what actually matters.
An old weak charger (5W) takes hours, and a cheap cable loses power on the way — slow charging and frustration.
A modern GaN charger with the right wattage (20W for iPhone, 25W+ for Android), a cable that supports full power, and a power bank for on the go.
PD/PPS support, multiple ports if you charge several devices, and a cable rated for your charger (USB-C to USB-C for PD).
Charge between 20% and 80% rather than leaving it at 100% overnight in heat.