One way that would be a compromise between shields or invulnerabilities and leaving things as is in regards to being spawn camped, would be to
1) Allow players to have a 360/Spinnable view of their spawn area before spawning in. So they can check for campers and decide if they want to spawn in or wait a bit.
I imagine the same sort of camera/view you get when you’ve been shot and are down on the ground but not 100% dead.
2) Randomize the spawn in points even more to be less predictable for campers waiting for victims. And also expand the zone in which one spawns in, say doubling it. As really the area in which one spawns isn’t that large.
For sake of argument lets say you spawn in each wave inside a 20 game meters by 10 game meters box, and within that box amongst 1 of the 8 possible positions. well doubling that to 40 game meters by 20 game meters and a 16 possible locations would help a bit at least.
These two suggested to me at least seem like a reasonable compromised between doing nothing and leaving the game as is, or implementing the anti camper death zones or extended invulnerabilities.