Over the past couple day's I've watched videos that really highlight the difference in player power scales.
I saw one pali with 9.4k HP. 910 PRR, 560 MRR and 400+ AC. If I didn't see it with my own eyes I'd swear it was impossible. He wasn't even buffed.
I watched a few r10 solos. Then earlier today I viewed a video from someone just starting to experiment with DDO. He was so proud of his broken build. He didn't think it was broken of course. it did what he wanted it to do.
Watched some other videos with power scales between the S&B barb to the 10khp pali.

To reach those upper levels, it really is all about knowledge base, time, layers and farming.
Layers of heroic PLs, epic PLs, racial PLs, full reaper trees, farmed out crafted gear, raid gear, and all that comes with having those layers.
get gud in DDO literally translates as grind moar and farm harder.

If one plays at a rate similar to my own, we're talking about a RL decade plus of grinding to get from the bottom to the top. That's how vast the chasm is today. A lot like rl society I guess.