MsPaint vs MyPaint the Open Sores Clone

Try to select an area in MyPaint.
Can't find it in menu or buttons.
Turn out its impossible.
Such advanced feature as MsPaint rectangle selection doesn't exist.
The issue is 4 years old now.
https://github.com/mypaint/mypaint/issues/31

>>6

I now have to use Krita

Elaborate, what's your work?