Comment by v9v

There are a few of these being sold as products: AGIBOT has some models like that (eg https://www.agibot.com/products/A2_W). One argument that could be made for legged robots is that these wheeled ones can only work in wheelchair-accessible spaces. Legged robots can also balance themselves dynamically: a wheeled robot may tip over if anything violates its static balance, eg. carrying a load high up and going through a steep incline, though I guess having the torso be tiltable as in https://www.agibot.com/products/G2 addresses that.

Legged robots overall have more implementation complexity, spend energy just to idle standing up, but can go over much more varied terrain provided the controller is good enough. There are ways to adapt wheeled bases to different terrains (eg. larger wheels, whegs, RHex, rocker-bogies) but we know how to use legs to locomote over many terrains from personal experience, while the perfect wheeled/non-legged locomotion system perhaps remains to be designed.

There's also the way robotics is going toward data-driven methods, which in some forms (ie. imitation learning) require human teleoperation data. Here having the robot mimic the human form makes the mapping from human joints to robot joints easier (compared to other morphologies where you'd need to figure out how to best approximate a human motion with the joints/joint limits your robot has, though this is not impossible).