It's not - as long as the DM favors both shorter and longer.
So that means that as long as a DM runs the same above the 6-8 encounter limit as below it - 13 encounters (+6 over average) as they do 1 encounter days (-6 under average), as many 10 encounter days as 4 encounter days, it's all good.
However, if I'f heard once about DMs that regularly go as much over than under I'd be surprised.
In other words, that is one perfectly valid mechanical solution that tables are not doing regularly for whatever reasons they have.
Ah, but "short days" + "medium days" isn't a balance. Short days favor long-rest recover characters, while medium days are at the design tested place and are more neutral. It would be "short days" + "long days" (+ any amount of "medium days").
And since tables do not seem to have regular adoption of "long days" (significantly > that 6-8), that's why there is a problem.
Thank you for providing such a great example of the issue, and since it is your own example I hope that you pay attention to it.
Let's see, using what tools I do have - frequenent feedback on ENworld - is less a view of all DMs then your thoughts without any backing form anyone else.
Sorry, that doesn't fly. I will gladly consider your point that it isn't widespread if you provide some sort of evidence at a greater level. If you don't have that or have never seen it, perhaps you should consider that you are only talking for your table and that this might be widespread.
As for widespread, again, no, frequency and ratios of forum posts are not predictive of how widespread a problem is in general play. Never has been. This can be observed on most any game boards whether they be RPGs or other. Your sample size is small, not representative and not driven by degree of problem so much as the fervency of often a small subset of posters who bring it up over and over.
if you have not seen this phenomenon, if you believe that frequency on forum posting is somehow relaibly indicative of the problem across the widespread play of the game among its player base, then all i can recommend is take some courses in statistics and survey protocols.
There is a difference between making conclusions on "what info you have" and making "good conclusions based on good data."
The reason i believe it is not widespread is that there are many more potently impacting choices for "mix for balance" than pacing the Gm makes all the time. Like i said (and i believe we agree) the choices of monster types can skew the balance between classes and characters even more than the pacing aspect does. yet GMs manage those all the time.
More to the point, GMs have been doing that since RPGs were invented.
Finally, again, i dont buy into your math of ther balancing out by doubling vs halving etc based on pacing. its a lot more nuanced than thatr and so no a 10 vs 4 is not on the same scale as a 2 vs 12. At best, if i were to try and math it out, it would be a lot more linear in terms of rounds or encounters - not exponential in terms of time, based on what i have seen over the years.
But in a very pragamatic sense, it is spotlight time more to the session level. There are lots of ways to balance that out without reverting to your multiplicative, as we both seem to agree.
problems get blown out of proportion, a useful trick for use on board furor but less useful in running actual games, the more one chooses to isolate singular elements and keep them out of context. that is what trying to limit the discussion to "pacing only tricks" is doing here.
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But again back to an earlier question, which of the following do you see as more limiting on the GM...
1 - The pacing differences currently established in DND 5e (short rest vs long rest).
2 - A defined linkage between encounters and short v long such as for example "you get an automatic short rest after every two encounters" and "you get a long rest refresh automatically after every six encounters." (assumes a set definition/criteria of encounter is also provided or else it is meaningless.)
Which of those do you see as more limiting the gm as far as pacing in his game?
my answer would be that the last one is more limiting because it removes it from the Gm control. It puts it as a set mechanical thing that creates one size fits all and removes it as being one of the tools the Gm can use alongside the others.