Why oil changes and not oil replenishment

Provided that the oil filter of an engine would be swapped every x time intervals as needed to be kept clean, I was wondering if, instead of removing all engine oil and replacing it with new (clean and uncontaminated), there would be any advantages in adding clean oil in shorter intervals and bleeding the same amount of the dirtier oil (probably left in the bottom most of the oil pan). This suggests that no oil leaks and oil consumption takes place. Would such a method provide better cleaning/flushing of the engine parts? The idea here is that replenishment will keep oil in an overall good/clean condition. If this method keeps the oil at an overall "cleaner" state would it help to prolong the filter longevity as well???