Powering via USB-C would be OK only on laptops with at least 4 or 5 USB-C/Thunderbolt ports, but such laptops are non-existent.
Laptops with only 2 USB-C ports, where 1 is blocked by the charger, are useless for me. When I have access to a power plug, I usually also want to use an external SSD and an external DisplayPort monitor, which need 2 USB-C ports.