I ran a single ongoing D&D campaign in college for four years, probably averaging 15 sessions per year. Advancement was slow, so the original PCs were in the low teen levels by the end of the game.
After college, I ran a long lasting GURPS campaign for about 10 years (interspersed with lots of shorter games). Characters were quite powerful by the end of it, and I remember that many players weren't even spending all of their earned points anymore. They were focused on the plot and their PCs felt fully fleshed out. Character points were banked for things that made sense in the story, whether small things (spending a point on Seamanship after an ocean voyage) or big things (adding a major new power after completing a big quest).
I took a hiatus for some years after that (new job, starting a family, moving across the country, etc.). Recently I've picked things up again. Ran a few short 5e campaigns, and then launched an 18-session DFRPG game. We might go back to it at some point, but we completed a major arc in that time. I'm now in the midst of another DFRPG game that's run about six sessions.
After college, I ran a long lasting GURPS campaign for about 10 years (interspersed with lots of shorter games). Characters were quite powerful by the end of it, and I remember that many players weren't even spending all of their earned points anymore. They were focused on the plot and their PCs felt fully fleshed out. Character points were banked for things that made sense in the story, whether small things (spending a point on Seamanship after an ocean voyage) or big things (adding a major new power after completing a big quest).
I took a hiatus for some years after that (new job, starting a family, moving across the country, etc.). Recently I've picked things up again. Ran a few short 5e campaigns, and then launched an 18-session DFRPG game. We might go back to it at some point, but we completed a major arc in that time. I'm now in the midst of another DFRPG game that's run about six sessions.