Win9x Notepad in particular can only load files up to 64KB in size (edit: and supports only ANSI encoding, no Unicode). There were some actually useful additions to it up until Windows 10 or so - for example being able to handle LF (in addition to CRLF) line endings. But yeah, everything added in Windows 11 is just pure bloat.
The reason being it is a plain text edit component, with a window around it, hence the limitation.
Notepad is so slow at loading large files that it crashing quickly is a feature.
The windows 7-10 versions that could open anything would just get stuck for half an hour when you opened the wrong thing in them, which was rather annoying.
I find notepad useful for sanitising clipboard content.
No bold text, italics, bullet points, invisible html.. Just get the text and can copy it to paste again somewhere else.
Ala Cmd+Shift+V on Mac