I've got you here. There are a number of ways to de-incentivize camping and game developers seem to have lost most of them in recent years. The first thing that should always be done is make sure that wherever each team spawns is VERY bad to camp in. Put in lots of lines of sight no blind corners you couldn't take another route to check. Many entrances to everywhere but not so many that you can't make an intelligent entrance yourself. You don't want to be walking into a room with 8 doors and having to put your back to 4 of them just to see the other 4. The next is making powerful but exposed positions around the map that if controlled well convey a large advantage but not so powerful that you couldn't nade someone out of it or retake it from the other team. The third is having power ups and power weapons positioned around the map to encourage movement. Think of Quake notice how they're almost always flying around the map timing power ups grabbing armor and weapons? Exactly. The problem is that developers are making really shit maps lately along with no real power ups/power weapons so it lends a lot of strength to the otherwise terrible strategy of standing still somewhere. You should be losing something every second you aren't actively moving to the next power position/weapon/buff.
Example you're playing against 4 guys that have a campy setup inside some room that you cant get inside of without all of the insta killing you. Some rocket launcher with 2-4 shots spawns every 2 minutes in the middle of the map. You grab the rockets on spawn walk up to their room and kill them all then probably kill them all off of spawn again. I bet they stop camping in that room and fight over the rockets next time if they have a brain. Now add other power ups and weapons on different timers in different places. Suddenly there's a very real reason to move about the map controlled by the developers so they can shape map flow around it and camping becomes a thing of the past.