When I came back to DDO after about a year off, I found the grouping experience to be really bad.
I had friends that certainly were willing and interested in running with me, but they were always getting tells to run in higher RXP/min groups (over R6), and the timing of the grouping I id have was Australian time zone, which didn't work well being fully employed here in the US.
The "wall" for me was that people that I didn't know that were willing to join my LFM's, which were always successful, found that I could not run them through content as fast as the groups that already had reaper points. People don't hang around long if they are earning 30% less RXP/min.
Being a very skilled player on a somewhat underpowered toon, the grouping options just weren't there.
Every time I have ever had a gap in power, I have always solo'd my way to relevancy before catching up with the crowd. Playing solo melee rogue on reaper without the latest gear and 20 reaper points is like licking a flag pole at -30F. The game play is just plain awful, because the "challenge" of reaper is really just a bunch of mobs all attacking you at the same time, without class tools to deal with that gameplay. It's really lazy design, with trivial ways to deal with - on the correct classes, each playing the same way every encounter because of their forced roles.
The "wall" was real for me with 86 past lives, and unfortunately the game has difficulty providing good play experience if you are not interested in running along in high reaper groups that your toon is not yet built for.
The "wall" was the fact that group play is now about attacking non moving mobs and never taking any risks, which is a sad reflection of the amount of decisions I used to have to make and the risk I used to be able to take, even when the game itself was unchallenging.
Nobody is going to "Get Good" when the gameplay or game experience is not fun, even if they are willing to put in the time and effort.
That's a loss for DDO player population and revenue, and really really bad design.
D&D is about designing an environment to challenge the player abilities. DDO is the opposite, it is about picking player abilities that ignore the environment and provide as little challenge as possible. It is sad how far they have fallen from the intent of a D&D like experience.