GoKawiilUSB-C laptop chargers can safely fast-charge phones, with limits
USB-C laptop chargers can be safely used to charge phones, and will speed up charging only if the phone supports higher-wattage fast charging via USB Power Delivery. Phones capped at 18-20W input won't charge any faster on a 65W or 100W charger, since the device only draws what it's rated for. Charger safety depends more on certification and build quality than wattage, as counterfeit units can pass dangerous voltage spikes and cheap cables may lack required safety components.