I have to admit I’m pretty ignorant in low-end laptops.

Business class laptops tend to be able to charge at 100W over USB-C, but often have a dedicated charging port as well (Magsafe for Apple, rectangular charge port for Lenovo, for example).

For any laptop that draws 100W or less, I believe they’re required to charge over USB-C in the EU. Barrel jack is cheaper though, so they can shave a couple of dollars off the price by using it, which could lead to significant profits in increased sales, since most of the competition is using the same basic parts.