The real issue is games just falling apart. Since nothing can really be done about this, I don't like counting them into the equation. If you only look at completed campaigns, I've found it depends on the DM and edition. IME, most campaigns have a story to be told, and the end level should be based on that.
In AD&D, a lot of campaigns I was part of were more open ended, going until the DM tired of it. Because of this, they tended to end between levels 10 and 20, but I ran one that ended at levels 30-35. In 3E, I found that most DMs didn't like higher level games, so ending closer to 10th level. Since 4E was better at higher level play, I found that most of those games were back to levels 10-20.
My successful 5E campaigns have been a variety of levels. My first one went to level 17, with a supplemental revisit adventure at level 18. My next one went only to level 7, but the story I wanted to tell was complete at that point. I just finished Vecna: Eve of Ruin, which ran from levels 10-20. For my current 5E2024 campaign, I have plans up to about level 10, but we'll see how it goes.
In AD&D, a lot of campaigns I was part of were more open ended, going until the DM tired of it. Because of this, they tended to end between levels 10 and 20, but I ran one that ended at levels 30-35. In 3E, I found that most DMs didn't like higher level games, so ending closer to 10th level. Since 4E was better at higher level play, I found that most of those games were back to levels 10-20.
My successful 5E campaigns have been a variety of levels. My first one went to level 17, with a supplemental revisit adventure at level 18. My next one went only to level 7, but the story I wanted to tell was complete at that point. I just finished Vecna: Eve of Ruin, which ran from levels 10-20. For my current 5E2024 campaign, I have plans up to about level 10, but we'll see how it goes.