No mob griefing survival keeps the mobs, but removes the collateral damage. Creepers still explode and endermen still exist, yet your builds do not get cratered or quietly dismantled. You lose the cleanup tax without losing the need to fight, gear up, and pay attention.
The tone shifts toward long-term play. Surface builds survive a bad night, public roads and towns stay intact, and people are more willing to live close together because one mistake does not permanently scar the area. Danger is still real, it is just aimed at the player instead of the terrain.
It also nudges progression and redstone. Some mob-based mechanics that depend on block breaking or block pickup will behave differently, and servers sometimes pair this rule with other tweaks to keep balance and difficulty where they want it. If you like survival pressure but hate random explosions undoing hours of work, this format lands cleanly.
