They certainly can do better prop disks. At least put in a side view texture to give them some depth.
Blackbox planes have never been particularly strong in the visual department so it’s kind of expected here IMO. Though even surprisingly Milviz with their otherwise excellent 310 has ugly flat prop disks.
Carenado with the C337 and the PMDG DC6 have probably the best prop effects I’ve seen in MSFS but they sadly don’t hold a candle to what DCS is doing by default. For a next gen sim it’s should really be a standard graphical effect tbh.