I know you joke, but in case someone has been unaware, there's Paint.NET[1], which is somewhere between MSPaint-on-steroids and Photoshop-lite.
In 7.5MB, it offers most of the features casual users need from a graphics program: layers, transparency, curves, etc. - all in a footprint (and startup time) comparable to that of MSPaint.
As an aside, this very proposed scenario makes me wonder how many users with more casual image editing requirements PaintDotNet has taken from Photoshop.
That has no use, as you can almost certainly not install and use it anywhere. .NET framework is an OS component you probably don't want to mess with. And Microsoft neither, given they only innovate in .NET Core nowadays.
I would love to see mshtml/trident spun off. While it is not the most modern design, of course, it does have some advantages for embedding and extending with everything having native COM interfaces.
two weeks later
"Show HN: I added transparency support to MSPaint"
two (more) weeks later
"Adobe shares plummet as users cancel their subscriptions to Creative Cloud by the thousands, analysts baffled"