I don't know much about Ashes of Creation so I cannot say.
What Pantheon provides that other games does not is the group-focused content. The grouping is role-based, you need your tank, healer, CC, DPS..etc. You need to CC adds or pull single or you're in trouble. When one extra monster is added everyone is on their toes. I've played this in EQ and I miss it so much in other games, I'm not a fan of extremely safe play style. I also miss the type of combat where NPCs are really strong and they take a while to be taken down. I've had enough of the gameplay where you jump into a group of 10 monsters and send them to oblivion with one single hit.
Also, VR stated that there won't be "hub-to-hub" questing which distracts people from grouping. I want to log in the game, invite my friends in a group and go hunting... again, just like EQ. To me, this is way more fun than reading or listening to a "story". I just played ESO and I simply just skip through voice acted content. It's boring having to go from Point A to B to C for infinity non-stop... alone! where's the fun in this?
Allow me to summarize these points so it's easy to read.
- Group Focused PvE gameplay
- Slow-paced combat
- Resources matter; you don't have infinite resources. Your healer goes OOM? you're in trouble.
- Roles; Tank, Healer, DPS, CC, Puller, Debuffer..etc.
- Slow leveling where you don't need to hit max level to start having fun. Just like EQ, you can group and seek out loot even at early levels; the gear will matter because you will not out-level it in 2 hours.
- Itemization; in the tenants of Pantheon's development philosophy on Itemization will be as I want it to be. This is hard to explain in one sentence but it's a big plus for me.
- Open world and very minimal instances. I'm tired of summoning my own McDungeon; again another thing that defies the point of an MMORPG.
- Non-linear dungeons. For WoW players, BRD is a good example of a non-linear dungeon while almost every other dungeon in WoW is just one straight line to the "boss", that will not be the case for Pantheon. Again, just like EQ.
These are just some of the things that Pantheon provide which I didn't see (all of them combined) in one MMORPG. This is just from the tip of my head I'm sure there are more.