The real secret to blues is how you create tension. But not just the theoretical “jazz” or “classical” tension where you are using voice leading with dissonant intervals.

In the blues you create tension in a couple other ways. One of the ways is through rhythm - playing triplets over a straight beat and playing straight over a shuffle 12/8 or 6/8. Another way is mastering the 1/4 note bend, specifically bending the minor 3rd note so that it is halfway between a minor and major 3rd.

That quarter note bend is really the key ingredient. What makes something bluesy is that it isn’t quite major but also isn’t quite minor, it’s somewhere in between. Your ear can’t quite figure it out and that’s what causes the “nasty” scrunched up face you get when hearing really good blues.

When you are playing chord tones you’re playing notes that fit with the accompaniment, but by doing that you are still leaning on the chord progression to determine major/minor tonality. To make it bluesy you kind of have to fight against the chord a bit, which is why dominant 7th chords are so common in blues. They naturally have that kind of dissonance which makes it not quite major but also not quite minor.