Technology for rich text formatting has existed for many many decades. It was not a part of Notepad. People using it were well aware of this limitation, and used notepad because that technology was not a part of it.
A non-used feature will still cause unnecessary data-traffic. At the very least to install it and update it periodically, more likely constantly because it will become part of the microsoft telemetry / advertisement profiling / tracking package that is called windows.
You want the feature. I'm interested, too. But I don't want the feature in notepad. I want notepad to stay as freaking basic as possible, because the main thing I (and I think other people too) like about notepad is the incredible speeeeeeed at which it opens on any device because it's "show text" and nothing else.