this thread is half of a suggestion in the suggestion summary for revitalizing old content, the other half ofc is a list of rewards that can be tied to these quests.
basically its content that already exists, but because there are inferior rewards tied to them, which doesn't motivate people to do them. Which is a shame. I will try to list the long quests mainly.
foremans (collar reward is inferior to prototype cyborg board)
nascense (multiple)
scheol quest (1 of the 2 rewards is pointless)
progression quests (debatable, but reward is automaticly gained by simply lvlin, so its often ignored content)
Dark ruins (most armor pieces are same or inferior to apoc/omni steel-ribbed)
Inferno Anansi quest
Arid quest
Neretva quest