@Hussar I provided you with monster crunch and a spreadsheet you could use for grasping things enough to perhaps ask even one question
relevant to the stories and anecdotes you noted with some specificity not to prove anything.. you claimed earlier that you were provided with stories and anecdotes... Pick one that you are interested in and ask pointed questions instead of suggesting vague frustration over not having enough details about some unstated aspect or details of some nonspecific stories or anecdotes. If you can't even manage that much it's strange that you would think it reasonable to expect an extreme like twenty to thirty rounds of details about a story or anecdote that you won't even point out or question with specificity .
No. You pointed me to a video which only had theorycrafted math. Zero actual play experience. Now, you can keep being condescending and snarky all you like, but, you still have not actually provided a single thing I've asked. All you insist on is your theory crafting must be accepted as gospel truth.
Twenty to thirty rounds of combat is about one level's worth of combat. Seems a pretty good spread to spot trends. At least, that's what I use when I examine my own games. I was concerned about a class being over powered because my gut was telling met that. Turned out, that I was entirely wrong once I actually started tracking things. The class was maybe a tad on the high side, but, overall? Nope, not over powered at all.
All your theorycrafting does is confirm your bias. Until you actually track things, I reject your white board theory crafting as nothing so much as smoke and mirrors. It's evidence of a potential problem, but, does nothing to actually explain what the problem is.
And, until you actually do the real work of testing the system instead of relying on percentages and probabilities, you cannot come to any sort of conclusion about why you are having these problems. Maybe it's the game math. Maybe it's the DM. Maybe it's a combination of the players. Maybe it's all of the above or maybe it's something else entirely. The "monster math" doesn't prove anything.
Again, if your math actually proved anything, we wouldn't need play testing. Every game would be a perfection of mathematics and any problem would be easily identifiable and corrected. But, your math doesn't prove anything. So, we need actual, in the wild, real world testing of the system to show where the issues are.