See what I did there? "Almost all" times? No. Definitely not. As far as "assuming" goes, I don't assume anything
Yes, I see that you're trying to dodge a bullet that has already hit your ass pages ago:
Camping is a LOW RISK HIGH REWARD strategy, that fails if the other team employs it, and that is deterimental to the game experience because it skews the odds of winning encounters in the favor of the campers.
...
[Teaspoon and silver platter mode on]
Who is the most advantaged in a head to head firefight:
The player behind cover, or the player in the open?
Just to avoid dodging:
The player behind cover has an advantage against the player without cover.
Period.
Who can pick his position on the map when encountering an enemy:
The camper, or the moving player?
The moving player does not decide where the camper will be hiding.
The camper decides where the moving player must move to cause an encounter to happen by picking a position with limited accessibility.
Who doesn't pick his position when encountering another player:
The camper, or the moving player?
The camper decides where the moving player must move to cause an encounter to happen by picking a position with limited accessibility.
Who is is spotted the easiest:
The player who moves across a stationary player's screen, or the player who is stationary on a moving player's screen?
The camper is harder to spot, because a part of a still image is harder to detect than movement on a still image.
Period.
What advantages does the moving player have over the camper, if any?
None, and that is not a discussion:
The element of surprise is not a factor unless the camper remains in the exact same position, which is a bad camping strategy unless there's a lot of room to move within the position, and both players have an equal opportunity to use tactical equipment, grenade launchers and move within their confinements (if any) during the encounter.