mamba
Legend
I don’t know, what one considers cool content varies quite a bit, and at high levels especially imo. Also, at that time characters are so powerful that challenging them will be difficult, and cakewalks are not cool, no matter what location they take place in.I think if there was really cool content at those levels, people would engage it.
Remember that a campaign doesn't have to "get to" high level -- you can start there.
D&D should just stop at level 10 or 12, most of their adventures stop there anyway. Focus your resources on what gets played instead of wasting half of them on stuff they rarely ever gets used