Moon mining’s been in the game for a long time, it just required POS’es with extractors. Now it requires an Upwell Structure to pull a chunk of the moon up from the surface and then blow it up into asteroid rocks, and once that’s done, it requires mining ships.
Moon mining has always been an alliance (0.0 alliances) source of income, because that’s where the valuable moons are. Now the mechanics for how to get the goo have changed, but the valuable moons are probably still in 0.0.
So, to answer your questions, as far as “lucrative”, from the alliance point of view, I don’t know. It used to be a passive system (set down a bunch of POS’es and collect), and now it’s an active system (CTA mining op, everyone bring your Rorquals, mark your calendars), so I’m guessing more “effort” for probably less payout.
For random solo players, if you try to bring your barge to an alliance’s mining op, you’ll likely get shot by their super-capital defense fleet. I imagine that’s not lucrative at all.