I just don't think the current FSS is good enough to spend much time with. I expected something else from the "exploration update", like comets, witchspace anomalies, exotic startypes, rogue planets, alien story, pirate stations. Sort of things and ideas that have been floating around since this game came out.
Yes, I think what you describe is what a lot of people were hoping for. But once they are found what then?
I spent most of 2017 out on the far side of the galaxy, I didn't dock for over a year, I spent a lot of it looking for fumeroles, and found maybe a dozen sites, all on tiny moons, no more than one per body. I was up to the challenge, but really it was too hard. In January 2019 I spent about a month testing out the new mapping & codex tools, I earned around 1.3bCr in exploration data (double what I'd earned in 2017) and saw so many fumeroles & other persistent POIs that I no longer bother to visit them for anything other than as a source of mats.
Maybe there is stuff still out there to be found the hard way, but I'm not going to be the one to find them with the current exploration toolset