If you haven't played in a while, try it out. They keep it interesting with the seasonal challenges and I am obsessed with gradually ranking up all my perks to max, but without resorting to an XP grinder map.
Custom maps are also fun. I run a server with custom maps and a dozen or so low gravity maps, which make things interesting. Look for "Flying Penguin's Low Grav KF2 Server".
"Turns out I’m 'woke.' All along, I thought I was just compassionate, kind, and good at history. "