Yea in phase 3 that’s the biggest factor from what I heard, I stopped playing SoD after phase 2. Not sure if their xp changes will change it at all.
It was much harder to find say WC groups on my server in later phase 1 and in phase 2 as well though compared to early phase 1 when tons of people were doing it.
SM in phase 2 made leveling zones sparse even early phase 2. Even with SM the number of people there went way way down after the initial rush. I think I saw 50+ people standing outside SM portals early phase 2 in a single layer. When I went on an alt awhile later there were maybe a few groups there outside the portals.
Even with all the people at SM during the rush, groups were usually looking for a short list of specific things so some people probably struggled to get groups even during the height of SM farming where a RDF queue would equalize dungeon leveling accessibility.