I'm talking about the claim that DMs who run games where you don't level up quickly are a problem. It's not that running big dungeon complexes like Greyhawk Ruins or Temple of Elemental Evil are characteristically different from a modern WotC storybook adventure and break down if the characters level up every 2-3 adventuring days, it's that they're just plain designed wrong, and DMs who want to run adventures like that like that are just doing it wrong.
Its a problem for me. If your players are completely content on playing games where leveling is slow, then that's how they should play. However, in terms of adventures meant for the public, relying on milestones that come out at a slow pace can be quite a problem.
Being 20th level isn't about adding 6 to your damage instead of 3. It's about being a demigod, a hero (or villain!) before whom the world kneels, so powerful that you and your best friends can waltz into the Abyss and challenge Demogorgon to his face. I don't see any fundamental reason an adventure has to be there in a year's time, such that it's a problem if, instead of defeating Zuggtmoy in direct combat, you're desperately seeking a way to banish her back to her realm and end the Cult of Elemental Evil once and for all. IMO, enjoying the adventure takes precedence over enjoying your character sheet, and if an adventure can still be fun while you're a somewhat mundane fella with a sword and a thirst for an adventure, that's not a problem.
You're talking about how long it takes in real time. Gotcha. But my players don't often have the ability to take things slowly because of their other obligations. Its not that the rush the story but engaging in things that were – in both story, roleplay, and mechanic-wise – a waste of time can be annoying when the players realize that they very well might not even see the climax due to a campaign that peters out due to real-life time constraints.
We don't know where we'll be in 3 years, so planning a campaign to take that long is basically never planning on them to see their characters to their conclusions. That's why a quicker leveling, and a quicker yet saturated adventure, structure is more appealing to me than one where being unnecessarily slow comes with the threat of a incomplete story.
You ever play Fire Emblem? The powers your characters get as they level up aren't much compared to D&D.
I have. Both the older ones (I've played shadow dragon but haven't beaten it but I have beaten Blinding Blade and Three Houses amongst some in-between).
The difference is that FE's stats increases are much more frequent and stats are insanely important in that game because the difference between 14 and 15 speed may be the difference between 11 damage and 22 damage.
Also, they have skill level ups which are even more rewarding and more frequent as they can start to add +20 bonuses to hits, avoidance, and even crits while also increasing damage by +6 on player phase.
These don't even mention the benefits that this has on classing and how much more powerful a swordmaster/assassin is to a myridon/thief.