I think the main issues was (and still is) poorly implemented progression. Current progression is a rapid and single-dimensional grind to 90, followed by a completely different (and much slower) grind to get good equipment.
The game drastically shifts halfway through, and most content is segregated into one of the two sub-games. WoM is two half-complete games instead of one.
Fetch quests are an awful way to introduce the first hour of the game and should be killed off - all quests should be some form of combat quest.
There might be quests where you’re asked to speak to someone/retrieve an item, but they should all involve an “unexpected” encounter with enemies to kill. Also more boss fights plz - or at least unique enemies.
On a similar note, early game combat should be made interesting by giving the player a full complement of simple spells much sooner - you should have everything up to and including high jump within the first hour or so. If combat is fun from the get-go, the rest of the game can take its time and we can have a level cap that takes longer than 6 hours of grinding.
In terms of reducing the divide between pre/post cap, I think the best approach is making common items easier to find and cheaper to upgrade. It’s completely impossible to actually mantain a decent set of equipment until you hit the level cap - stuff costs too much to upgrade and items obsolete too fast for anyone to keep their armour and accessories up to date.
Level cap content should be the rare stuff (and that can stay expensive and impossible to find), but players should be able to keep a full set of equipment up to their level as they progress.
More specifically, items that give percentile stats (Magic Size, Agility, etc) should be reworked so they’re actually useful in the earlygame, and not just a noob trap that makes 80% of the items in the game worthless. Logarithmic scaling pretends to fix this but really doesn’t and just causes more problems - what we actually need is AA’s method of no scaling.
Items for percentile stats should have a simple multiplier (say, +10% magic size), and a small amount of power or defense. Upgrading an item improves the power/defense, but the multiplier stays the same - later game items can have higher multipliers (so endgame magic size gear gives a bigger boost than earlygame gear), but the multiplier isn’t improved by levelling up the gear.
Finally, something I’d really like to see is expanding Teamwork (the quest sharing feature nobody ever uses) to more areas of the game, and making it more effective than solo grinding. Currently it’s way slower than normal questing because you’re getting halved XP and finding/completing quests isn’t any faster, just easier (and all the quests are already easy). Getting another friend to join you should always make things faster for everyone - even if only a little.
My best experiences in this game have always been playing with friends and organised events (like ice fishing). Playing with friends is fun and should be rewarded, and making friends should be rewarded. Guilds should be more than just a number to grind and flex.