In addition to the raw compute power, the HP laptop comes with a:
monitor
keyboard/trackpad
charger
windows 11
active cooling system
enclosure
I've been looking for a lapdock [0], and the absolute low-end of the market goes for over $200, which is already more expensive than the hp laptop despite spending no money on any actual compute components.
Granted, this is because lapdocks are a fairly niche product that are almost always either a luxury purchase (individual users) or a rounding error (datacenter users)
[0] Keyboard/monitor combo in a laptop form factor, but without a built in computer. It is intended to be used as an interface to an external computer (typically a smartphone or rackmounted server).