Reply To: Why can I delete but not disolve a cilinder cap?

Honestly…

I have been using Blender for over 13 years now (mostly Modeling) and I still don’t know how Dissolve works exactly 😉

If your interested though, you might want to take a peek at the Manual: https://docs.blender.org/manual/en/4.2/modeling/meshes/editing/mesh/delete.html#dissolve-edges There are some extra Options available with F9. Also, in your example, you could do this: