How to remove this component from modern pages, banner or whatever it's proper name is?

Hi, its the default command bar for all the lists and libraries. Its not recommended to remove this bar. If you really want to remove the command bar, then you can do it by creating an custom SPFx application customizer extension and then you can have a list having the list name whose command bar has to be removed and you can also check for logged in users to remove the command bar for selected users.