[Eridrus]

I have been part of exactly one successful non-school study group: going through the Sutton & Barto RL book.

I was highly motivated to get into ML at the time and also unemployed. Since being gainfully employed doing ML, my motivation to consistently find time for study groups of all sorts is much lower.

I liked the study group because I found the material somewhat challenging and appreciated having some folks who I could talk to about it.

The study group had ~6 people in it iirc and was offline. I did the exercises, but almost nobody else did.

Which is to say, I think study groups are hard to sustain because dedicated sustained effort is hard to sustain overall.