It's common for newer gaming laptops to have both USB-C and proprietary charging capability. When not under load, the 65W or 100W suffices for charging.
If it pulls more than 240W from the wall it can use USB-C PD, though common chargers only go up to (or just a bit over) 100W.
My charger uses 180W for my personal laptop. My office laptop already has USB C and pulls 65W.
There is an option for more than one USB-C port.
Chargers for 240W will appear eventually, standard was approved few months ago.
If your gaming laptops needs more than 240w you could use multiple 240w chargers. I believe gaming laptops use multiple chargers anyway.