Because it's lightweight and portable. :)
Notepad2e is just a small exe file which doesn't require installation. This allows me to run it on my work PC or random work VMs without filling out any paperwork. And on my personal machines, I can replace the OG Notepad with this by renaming notepad.exe in the Windows folder, so when I press Win+R -> and type "notepad", it fires up Notepad2e. It launches just as quickly as the original Notepad, and doesn't use much RAM either, and provides most of the features that I'd commonly use in Notepad++, such as text transformations, syntax highlighting, large file support and live monitoring (which makes is handy for viewing logs). With this, I don't really have a need for Notepad++ - if I want more features, say I'm working on a proper coding project or something, I'd use a proper IDE like VSCode, but otherwise, Notepad2e satisfies most of my text editing needs.