[New player] Necro vs Revenant
Neither class is Meta in PvE, and Necro is merely interchangeable with Ele in WvW. PvP doesn’t matter, because its always a mess.
That aside, PvE “meta” is just code word for Raids…. because class choice makes no difference outside of that. For Openworld its really a question of minimum efficiency; which lends toward certain build concepts, but not demanding min/max performance.
As for long it’ll take to unlock Reaper…. how long does it take you to get 10 Hero points? Maxing it out, you’ll need 250 in total.
Rev is only capable of middling damage, and Herald Utilities are actually the strongest personal DPS boost due to its casual might generation. Assassin utilities add mobility, but that ultimately doesn’t matter in PvE, since very few enemies move around. Unless when you say “mobility” you mean swiftness…. in which case glint can stack permaswiftness.
On further thought…. there is added irony that “meta reaper” is just condi necro with Reaper being used for its boost to condi damage. Power reaper in open world is a beast though….. almost unkillable, and has respectable damage output if you build it right. Decimate defenses, and Valks gear….. should be able to put two and two together.
And full disclosure, I run Rev in WvW for Mayllax resistance, and bumming around in HOT maps.