fates, and with the addition of the shared fate system in Shadowbringers, you have an incentive to run them
but then people would argue that it's boring

I think it would be nice if they expanded open world content
GW2 is pretty fun in that respect, and maybe they can do something akin to the mastery system now that we've reached level 100
The developers did seem to not want to go further than that

I'd also like to see them implement something like points of interests, and map completion