There are several scenarios where worlds and filters can be useful.
Many actions obey the world and filtering. For instance store and delete.
When any store or delete action is used, then the action is filtered through the selected world and filter. Only the fixtures and attributes passing the filtering can be affected.
For instance, having filters for each feature might help to program different values into different cues or cue parts.
Sequences can use worlds and filters.
A world or filter can be assigned as an input filter. This limits what can be stored in the sequence.
Worlds and filters can also be assigned as an output filter. This limits which fixtures and attributes the sequence sends values to during playback.
Preset pools and single presets can use worlds and filters as input filters. This limits what can be stored in the preset pool. This is really interesting for the All preset pools.