No offense, but is every post you make some plot to make everyone on this forum violently angry? Because its working. You can’t tell the #nochanges forum changes and expect them to roll with it.
However, I do like the way Final Fantasy XIV did (been a while since I played) things if you wanted to play with a friend of significant level difference.
The higher level character is dropped to an appropriate level for the instanced content, including losing any abilities that they had at the higher level.
For classic to succeed at all, it can’t have changes. The more changes it has, the less ppl come back to it. Older players won’t touch it at that point, and retail players could just play retail. So, even if it was a good idea, it wouldn’t work.
I’m actually a fan of limited open-world and dungeon level scaling (but not ilvl scaling, hate that crap) in retail, but also understand the pushback here.
The thing is that there were certain, “Vanilla” ways of solving the problems you are talking about in the OP. If your friend wanted to play with you and help you level, they would carry you on their 60’s through a bunch of dungeons, or if that was too boring or too slow in terms of leveling, they might let you tap a bunch of mobs in the open world, gather them up, and then mow them down before they killed you so you got all the experience.
If it was important to them, and to you, to have a challenge inside the same dungeon because cheesing it was boring, they would level several alts and leave them at different levels, or leave an alt slot always open so they could start a new toon with you, or whatever. If you were not in a guild that had a “help n00bs level” focus (and yes, there were guilds out there that did this, and people who enjoyed helping n00bies in this way) then you would spam general or the LFG chat channel to see if there were any parties with an open slot about to enter the dungeon or whatnot.
It was a problem, in essence, to be solved by the players and the community and not by game mechanics. Level scaling in retail has, in many cases, become a shortcut to that sort of problem solving, much like the LFD and LFR anonymous/remote queueing function that came in mid-Wrath.
I’m level 48 and want to help carry my friend through wailing caverns, but the mobs are all my level and I’ll be rewarded with level 16-19 loot. He’s better off finding another player to group with, because I won’t benefit and it will take just as long. Good thing scaling was added so I can progress the numbers in my character tab, but never progress in the power I have over the environment. Sounds fun and why I left retail for Classic.