That must be a chunky laptop lid! It’s not just thickness, it’s also parts availability. Most laptops are super thin so the market for USB webcam daughterboards is optimised for shitty, thin laptop cameras.
There’s also post-processing: a webcam of the same shitty image sensor size can look a lot better if the raw data is processed better. That’s why many Qualcomm laptops look to have better webcams even though the camera quality is just as bad, they just use the skills they’ve gathered in the mobile space to process the image into a more pleasing image.