Coax might be better in somebody’s system but another person might have the opposite experience. Toslink might be better when you have long connections, ambient electrical noise or ground loops. Coax might be better when you have system noise. Typical coax should be either very short <1ft or long >1.5m to minimize jitter caused by reflections in the cable. Reflection occur on boundaries of characteristic impedance. Because of that cheaper cable might be a better fit than expensive cable (better matching characteristic impedance). It is a system thing and what works for one person may not work for another, unless they have identical systems in the same room.