Why are ultrabooks often used synonymously with thin notebooks?

I don't quite understand that, after all, all notebooks with a Ryzen processor are excluded.

https://en.m.wikipedia.org/.../Ultrabook

Why do you call handkerchiefs "Tempo"?

https://de.wikipedia.org/...eonomastik

As far as I understand, Ultrabook are the counterpart to Macbooks. It is a proper name of Intel.

It's like saying "I blow my nose at a pace", but pace is just a brand name for handkerchief.

Exactly my example.

Ultrabook was created in connection with Intel processors. Basically, these small, very mobile laptops are also called subnotebooks.