A lot of this.
Just a reminder to the people that are commenting on Delve viability - lets remember than any class or spec can clear 8+ delves with Brann doing the heavy lifting and is not indicative of a class’s performance. Delves are casual content and designed to be just that.
Destruction (Recommended)
Destruction is currently the main go to in Mythic+ and seen a lot in raid, not because of its big numbers (it actually sims the lowest of the 3), but because of its on demand casts (Shadowburn, RoF, Conflag, Infernal) in a very movement heavy season. Tomorrow’s buffs will make it the clear front runner if you care about your numbers.
Affliction (Viable)
A decent choice for Mythic+ but its numbers are somewhat lacking in higher keys for long boss fights / low mob HP can make it difficult to maintain high dps when you have to reapply dots outside of Vile Taint windows. Also shines in the Silken Court if you choose to raid.
Demonology (Not Recommended)
Currently simming the highest but performing the worst due to its dated kit design. Avoid Demonology for Mythic+ as you won’t be able to get half your spells off and align your summons optimally - but it has its place in certain raid fights if that interests you.