If camping is too effective, then the map or weapon balance is what needs work.

For example, of people are camping spawn points, why is the spawn point so easily accessible at all? Why don't players spawn behind cover with multiple exit points? Do they not get temporary invulnerability?

Or camping objectives. Why is there only one, easily defended path to the objective? Why isn't there a path for you to sneak up and just stab the camper in the ass while he's staring down the scope? Or just walk around him and ignore him completely?

Watch some professional CS:GO. Those maps have been refined and balance-tweaked for decades. You can't just camp one objective because there are two objectives. Every good camping spot is still leaves you exposed to getting flanked. Even with arguably the most OP camper's weapon in any competitive game - the AWP, teams still only run 1 AWP, maybe 2 at most. Simply because camping alone isn't effective.