At what level do your campaigns tend to end?

[Resonant Curse]

Generally the older (35+ish) crowd that started with the older editions prefer the slower pace and generally all have set homes/jobs, which does lend itself to longer campaigns that can last decades. Younger players tend to have started on 3rd/tail end of second computer games like Baldur's Gate and are used to the faster 3rd+ speed. The faster speed is better suited for the high school/college crowd that can't necessarily expect their friends or even themselves not to have moved out of the area any given semester/year.

Heh... "Younger" players play 5th now. You're a bit out of date.
Generally, people tend to play what they grew up with. Switching editions is a huge undertaking and only gets worse as you get older and set in your ways.
We get a lot of 3.5/PF here because that's the edition of the last major setting. We also get some 2e players because that was where RL started. The more adventurous among us have branched into 4e and 5e, but many just stick with what they know.

(42-year-old 3.5/Pathfinder DM here... Campaign running through 28 weekend long sessions over the past 16 years, going from 1st level (3.0) to 11th (PF) so far, with no end in sight...)

I meant anything post 3rd edition by 3+. I certainly wasn't saying that there aren't a ton of fantastic 3/pathfinder/5th games run or played by the group around for when 2nd or older editions were the norm. I know a player in the 2nd edition game I am a player in at the moment (I prefer 3/3.5 myself due to the easier customization for players and dms even of monsters) that is dming a 5th edition game. It sounds like it is a great campaign, unfortunately it falls on one of the days I have my daughter so I can't participate. I was more saying that *generally* the older players are a lot more into the slow grind play style that 2nd edition had and requires tweaking of experience a lot more for later editions to accomplish. The Ravenloft setting does lend itself to a bit slower xp gain too since it tends to have somewhat fewer combats.

[Resonant Curse]

I do understand too that changing editions can be a big jump. I am 31, so got into D&D with second edition computer games like Baldur's Gate, Planescape Torment, Icewind Dale that handled most of the rules without you seeing the exact numbers unless you looked at the character stat pages and started pen and paper in any serious way with 3rd edition. 4th was a huge jump and everyone I know didn't like it so we all abandoned playing it pretty quick after trying it (I still own most of the books for lore purposes) and 5th is a close enough to 3rd that I can pretty quickly navigate most things with only having done a few of the Adventurer's League games at cons and some of the open playtesting when it was being designed. One of my coworkers that is older was running a 2nd edition game and I hopped in. Learning 2nd from a newer standpoint is way harder between not all die rolls not having high is better, way more charts, and fairly godawful setup in the core books of where to locate things.
The majority of my friends that are close in age (unfortunately most that played moved ost college) did move up to 5th, but there are a number that stayed in 3.5.

[Gonzoron of the FoS]

I meant anything post 3rd edition by 3+

Ah, I missed that "+", sorry.

[Wolfglide of the Fraternity]

I do understand too that changing editions can be a big jump.

I first got into D&D when I saw a basic game box set in a store and asked my parents about it. Their reaction was something along the lines of, "Uh oh."
I later got a kit with a paperback copy of the 3.5 Player's Handbook, then I requested the DMG and Monster Manual. My parents did not know about the differences between editions, so I got a 4th edition Monster Manual and a 1st edition AD&D DMG, which made playing super confusing.

Once I found a relatively stable gaming group at a local store, I played 4th edition for several weeks until a near total party wipe derailed the campaign in early levels. It wasn't my fault---not that time---but I did have to kill another PC.

After a Call of Cthulhu hiatus fighting the King in Yellow, there was a return to 4th edition for a while, then someone started a 3.5 campaign which must have lasted for a year or more and went all the way from 3rd level to 20th (switching DMs multiple times). I went through ten characters (and six deaths on the last one thanks to the reincarnate spell, if I remember right). That campaign did involve a short stint (three of my characters murdered by the rest of the party) in Ravenloft.

I don't think I have been in a campaign that has lasted as long---level-wise---ever since.