Notebook arguments?

My notebook broke but my parents think a desktop PC is better you know the arguments to convince my parents

It is portable and can be used better for school / university

As a rule, you don't need a laptop for school or university. Notes are much easier or faster on paper and you miss less when taking notes. At home you can then prepare the whole thing in peace using a desktop computer. If necessary, data can be carried home by stick.
Desktops are significantly better from the ergonomic side. Both keyboard and screen can be optimally arranged here and thus reduce the risk of serious damage to the spine. With laptops, the distance to the monitor is simply too short and the monitor is too low. Furthermore, the keyboard is rigidly coupled and can't be moved as required. Mouse pads cause wrist cramps.
Due to their small size, the components of a laptop are exposed to significantly higher temperatures than those of a desktop computer. These usually have a lot of unused space and are therefore much easier to cool. In addition, they are cheaper, defective modules can be replaced much cheaper, usually even yourself.