You can sort of emulate the SAI's blend brush inPS as well, using the mixer brush with different settings and brushes.
That's what I would use to blend if I didn't use SAI, together with airbrush and lowering the opacity of my brushes.
One similar program to SAI is Clip studio paint (or 'manga studio' by it's other name), it also blends like sai. I have it actually, but I still haven't
gotten myself to paint anything big with it. I've also tried Corel painter when it was available for trying purposes for one month.
It isn't the easy or fast to learn to use thought, and I found it's interface a bit confusing. I got the feeling that if I wanted to
produce anything decent with it, I would need to spent weeks just to learn to use the software itself and get comfortable with it.
A versatile and great program for sure, but takes time to learn. I found I still used old and simple Sai when I felt I needed to get
things done fast, with those other programs I spent time just trying what this and that button would do and arranging my work space
panels so that they wouldn't bother me
. But as I'm most comfortable with sai and then photoshop, I'll stick to those for now as well.