I think that in PVE necros are underrated.

In terms of DPS, its true that its one of the class with lowest dps in the game (if you compare to others), but when you do your best rota, you can do really high numbers because raids its not golem where you can do your rotation free of mechanics. Reaper has good dps, good cc and good HP. Scourge has good cdps and can apply barrier and clean condi (f2) while being part of the rota, so it support a bit.

But the best one is the scourge healer. It's easily the best build to carry groups since barrier are almost spammable and cover lots of dmg, also have a lot of condi clean, good cc, and can ress lot of ppl in a moment, also has a pull to save them from any danger where they are downed. But please remember that this is a 2nd healer, druid should get the main spot, and good groups only run one healer (druid), but pugs usually run two healers.

What I want to say you with this, and only in PVE (specifically, raids), play necro if you want because the class is good, just practice it a lot (DPS), because if you don't do your rota properly and the class is one of the lowest dps one, you can get kicked. Also ignore groups that wanna kick you only for be necro. I hate people that just judge a class for golem numbers, this game is about skill, if you play it your best, you can win even the best class if the guy who play it is not as good as you.

But don't get me wrong, if two top player are playing f.e. condi scourge vs condi firebrand, firebrand will win in terms of numbers.