Come back in what sense? You mean the activity at Daemonheim or?
If you mean the activity, you'll only see it buzzing during bonus exp weekends because daily-scape is more efficient otherwise.
12 min Larges with your average PUG are 150k+ if high Prestige doing high Occ/Low warp.
Extended DG challenge is 200-350k exp per day for just 6 minutes, maybe 8-10 if you're slower.
Also add Sinkholes into the mix with daily reset tokens.. They've effectively made it inefficient to actually train the skill. It is what it is, I guess.
As for the other question: Cockroaches weren't removed, they were moved to the Player Safety Stronghold many moons ago:
https://runescape.wiki/w/Stronghold_of_Player_Safety