That's not the acceleration wotc designed. They took a game where most groups are probably only going to get to about level ten or so give or take a couple & have it an advancement rate that tries to assure that within a year of regular sessions you can get an additional dozen or so levels give or take .
And I have seen this alleged "acceleration" in all of
one campaign. The one I'm currently playing in, run quite graciously by Hussar of this very forum.
When folks say 5e's issues lie heavily on the GM side of the equation,
they aren't joking. There are numerous parts of 5e that are simply NOT used the way they were designed,
consistently not used that way, despite the fact that doing so actually makes the play experience worse for most people who play it--and even sometimes worse for the person
running it! (I'm particularly thinking about the skills system there, and how it is very poorly used by a large chunk of 5e DMs, but that's just the most prominent example.)
I find very odd the love of level 1 play that some people have. Or even level 0 play! I appreciate that it exists, but I don't want to spend a long time there.
While I surely do not share the
interest, I consider it an absolute requirement that any future full, proper, no-pretense, we-actually-recognize-it-as-one edition of D&D provide full-throated, well-tested, effective rules for "Novice Levels" or "Zero Levels" or whatever folks might want to call them.
I consider this no less essential than anything that caters to my own interests, even though I would probably never make use of those rules myself. Because part of a commitment to creating a system that is well-designed for a wide variety of players is stuff like that. Spending development time on things that
I don't care about, but which I know would make a HUGE difference for people with different interests.
The initial scheme that Wizards designed was basically:
1 session for levels 1 & 2,
2 sessions for each succeeding levels
(Although a few would take longer. Sessions being roughly 4 hours in length).
So, to reach level 20 takes 36 sessions or thereabouts. Except possibly longer.
I'm aware of what they aimed for. I have seen it, as noted, precisely once, and that only extremely recently.
Can't speak to 5e specifically, but IME low-level play in general can be a blast because players - not yet being too attached to their characters
Gonna have to stop you right there. I am attached to my character before a single die has hit the table. I am not able to roleplay a character to which I have no attachment. It would be like trying to write a poem about something you literally could not care less about, or trying to give an enthusiastic performance with a song you genuinely feel no emotions about whatsoever. I just
can't do it.
- will have them try the craziest things; which puts the entertainment value way beyond the high end of the charts.
Whereas I find that you get them to do the craziest things, all throughout the campaign, by ensuring (a) they know they won't be harshly punished for creativity, (b) they feel confident that they can accurately gauge the risks involved, and (c) they actually feel comfortable taking risks, because they know you don't just willy-nilly take away the stuff they're invested in (even if you may torture them ruthlessly over some change or cost

).
When creativity is rewarding, when players play in good faith, when DMs support sincere enthusiasm, when the players know (as Jafar so
kindly taught us!) "after all, there are things SO much worse than death!"--
that's when you get players doing the crazy stuff, gladly throwing themselves into devil-pacts and swinging from chandeliers with Flynn-ly abandon and smooching dapper swains left and right.
Instead of grubbing for every advantage they can get, they trust you, and you trust them--they trust you to not shut them out of participation, to not destroy the anchors that tether them to the experience, and in return, you trust them to adhere to the spirit of the game, to do what is dramatic and exciting and productive rather than merely what is safely sterile and dully efficient.
One might even say you encourage them to make magic feel magical again.
My preference is for a campaign whose real-time duration is "open-ended" and measured in years. To achieve this, the base levelling rate has to be much slower than the 3e-4e-5e model has it; and there's other tricks a DM can use to slow the overall advancement speed down. 2e as written, and 1e if one doesn't give xp for gp, got it right.
That is also my preference, unless I'm very specifically aiming for a full 1-to-max adventure path. (Someday,
someday I will find a 4e group willing to run Zeitgeist. And it will be beautiful.)
It doesn't at all need to be slower though. 4e has 30 levels. Three years is 36 months. Accounting for occasional delays, e.g. say 3 months total of missed weekly sessions (aka about 4 missed sessions per year, which IMO seems pretty conservative!), running from level 1 to level 30 (gaining 29 levels) means gaining around one level per month, give or take. Since 4e characters start off
actually competent and fulfilling their class concept right away, as opposed to feeble and inept and extremely likely to die, there is no issue with spending four weeks at 1st level. (And yes, I have lost
multiple 5e characters before they even reached level 2, and I even effectively lost a particular one
thrice in one campaign!) Indeed, it can be quite pleasant to stick with a focused skillset at first so you really learn exactly what you can do with it before moving on.
But being trapped in a world where one bad roll can literally mean the end of your adventuring career, where death is not merely a danger but an everpresent, constant, paranoia-inducing threat? I don't enjoy that in the least--and stretching it out over
months of play? God, I'd almost rather you
actually torture me than do that. At least the latter gets it over with.