[andwur]

That's inaccurate for standard thickness drywall sheet, which is usually a 20kg maximum parallel load (e.g. vertical for a wall) regardless of fixing method. Orthogonal load is even less. You might be able to attach a TV or cabinet but it would definitely not be safe, any additional weight or dynamic load would quite likely rip it off the wall with no warning.

The recommended approach for anything with moderate weight or above is to anchor to the studs and never rely on the drywall itself for retention.

[c0nsumer]

I suspect they are meaning because it's uniform you can easily find the studs through it and fasten things directly into them.

An uneven wall material (plaster on lathe, or even plaster on drywall as we have in most of our house) can be quite a hassle to find the actual timbers/studs behind.

[hedora]

Modern plaster has the same properties, and works well with stud finders.

On a related note, if you can find a strong rare earth magnet, you can use it as a stud finder. It'll be attracted to the nails used to hold up the drywall / plaster backer boards. They sell purpose built ones with felt backs + built in bubble levels if you want to get fancy.