Tabs are fine I guess but also: it's NOTEPAD.EXE. Its purpose to be super primitive and launch in 2 milliseconds and give you a place to paste or type some text real quick. Anyone who needs a good text editor with actual features will just download the good text editor of their choice.
Simple example of the newly poor UX. I try to start notepad to jot down some scratch. It sluggishly reopens whatever it previously had open (e.g. from before a reboot)...and in doing so, doesn't actually create a new document for me.