For me, like the "popup message" if you do not select articles but use the edit button, is necessary a "popup message" if you select more than one articles an use the edit button.

If you select more than one article isn't it better to disable the "Edit" button?

This is a long standing issue. In the same way if you select an item you can still use the new button and if you do not have any items selected then the other buttons are not disabled. And there are other places where a button is enabled but doesnt work if you have more than one item checked. Every attempt to change the UI for this has been rejected in the past sadly

A resource in usability is group by design similar behaviors, if NEW and EDIT can not act with several selections of items and the rest of the buttons yes do it,
Change the design of the EDIT button.

In this way the user understands that the gray buttons behave similarly.

But my vote is to remove the EDIT button.
Nobody click in the check item and then click in the EDIT button, all people clic in the item title.

Nobody click in the check item and then click in the EDIT button, all people clic in the item title.

You have no way of being qualified or to possess the knowledge to make such an absolute statement

Love Joomla is a great qualification, but we all want in Joomla the best UIX, all people or the 80% of the people in terms of usability is the same, obviously i speak in absolute terms (exaggeratedly), there is a lot of expectation by Joomla 3.7 for UIX and the Custom fields, sorry for my way of expressing myself, but Brian, we want the same.

I ask you not to value as i express, the important is identify an improvement, i do not speak any English and the translator of Google is a sucks.
Sorry another time for my exaggeration.

Closed as this has been addressed in J4