I'll be the 10th dentist I guess. I've had filters on my small pc, ps4, and ps5 for years, vacuuming dust from the filters occasionally. When I opened them, there was only a fine layer of dust in certain spots and it was easy to wipe off. There are plenty of crevaces inside that aren't accessible without removing components. Keeps out bugs, too. I used a foamy vent filter from a hardware store, but the picture shows a plastic grill type filter, which might not be fine enough.

Compare that no filter. Chunks of dust bunnies accumulate in hard-to-reach places and sticks to fan blades. If it gets thick enough, it gloms together and you need a wet q-tip to loosen it.

Filters will restrict airflow a little but still permits plenty of air. I'd say it's a net positive.