Part of this feels like it's still a hangover from the changes to DoTs. If I take Magplar as an example, a "standard" DoT like Destructive Reach is barely worth taking over Sweeps (a relatively strong class spammable, especially factoring in BL) so to push out the best damage you end up wanting expensive AoE skills like Blazing Spear (for the BL procs), Mystic Orb or Solar Barrage (for the constant Empower), really driving down overall sustain unless using BFB.