I agree. Sight reading does open up avenues - and my ultimate goal is improvization. I love to analyze various pieces and understand the functional aspects of tunes - so that I don’t need to rely on reading or remembering.

That is why JazzSkills.com really worked for me. You can find several free videos on their YouTube channel - https://m.youtube.com/@JazzSkills

I almost gave up on learning and playing music after struggling for years / decades - and by happenstance came across JazzSkills few years ago. And since then every single day I get joy in learning and playing music.