I can't say much about other websites, but I do take in person lessons mostly because my improve skills suck. I don't know how one would go about learning improve skills from a website. You pretty much have to play with other people.
What haven't liked in the past is instructors who do a quick transcription in the half hour slot and send you on your way.
Or you get a Mel Bay book and are told to "Go work on this stuff" They do not teach.
I like things explained, why do these chords go together? It's not a I IV V, how can that work? I went for a long time not having any idea what I was playing and got really tired of it. Find a good teacher.
Interests? I have a huge interest in theory these days. I don't know why. but I do.
Paul