There are many available but unfortunately they are usually more expensive for thee same hardware

Well, is not super common for sure, but Dell sure sell the same laptops with Ubuntu pre installed, they're a bit cheaper too. At least in here South america they do, pretty much every single computer they sell has a Linux option from the box.

But I also can't think of any other big brands that also do that, so you have a point, Asus and Acer have some models, but they're harder to find, even online.