WoW Classic is the World Of Warcraft that i grew up with and also the best version of the game, over the years expansion after expansion has been added and changes have been made to appeal to the masses that have continued to evolve the game into something else entirely.
If you have tried both current version of wow and the classic experience its easy to see straight away how much the current version holds your hand and skips you through tons of content without much thought, I've bought every expansion to date for the game except for Shadowlands as i know its just more of a rushed experience to get to the end level and group with a bunch of randoms that ruin the experience half the time because they're either not willing to commit 100% to the run or downright toxic.
There is no doubt some good community in the game depending on which guild you belong to but i must say that there is far more elitism in retail than classic that really dulls the whole experience end game, I found myself running old dungeons to try and get some new mounts or new appearances of gear and that was about the extent of my end game experience so then you would start a new character to level but then that would be a mess because the whole thing is rushed now.
You can literally kill like a few boars in retail and go from level 1 to 5 in less than a few minutes, in Classic WoW this can take up to a hour while you take in the sights and really enjoy your time killing those boars while wondering what kind of loot you might get to upgrade your character.
I have 1 of every race and class in the game and im taking my time with every single one of them and loving the experience even leveling professions on every single one that is useful unlike retail because the gear in classic has a huge impact while leveling whereas the gear in retail only matters at the end level which by then most people myself included lose interest as there doesn't feel like much to do other than to run dungeons and raids to try to get more of it.
If your looking for an experience that doesn't hold your hand and makes you value everything that you achieve or get right up to level 60 then i recommend you play Classic
Im more excited for the burning crusade than Shadowlands which is currently out at the moment because i know that even though the expansions brought about change it wasn't until the 3rd expansion Cataclysm that things started to go downhill, the fact that blizzard decided to level crunch the max level to 60 in the retail wow tells me that they're trying to take aspects from Classic but its so poorly executed because of how easy it is to level.
Just my 2 cents