Lynx have prominent ear tufts because they help to communicate. That is my assessment. There is no official assessment. You can’t look up the answer in a book or on the internet; until this page was created.
What is the basis for my theory? Using Darwin’s theories about evolution it is normal for the anatomy of any creature to exist for a specific reason which aids survival. So the existence of large ear tufts on lynx wild cats should be to aid survival. That said evolution is not a strictly logical science.
Perhaps the ear tufts serve no purpose. That is one possibility but I reject it.
Another reason why I have said that the ear tufts help in communication is the input of a American lady, Deborah-Ann Milette, who used to own tame caracals. The caracal is a medium-sized wild cat with the most prominent ear tufts of all the cats. She says that they are for communication. You can read story by clicking on this link.
A further reason is that many wild cats and some domestic cats have an eye spot on the back of the ear flap. This exists to signal aggression when the ears are turned away from the aggressor showing the spots. The ears are partly flattened to protect them during the ensuing fight. This supports the view that a cat’s ears can be used to communicate.
As for the lynx, the ear tufts might be employed in close communication with other lynx cats. They may be reinforcing signals in conjunction with certain sounds and postures (body language). Good communication aids survival.
It would be nice to see a study on this. Do you have your own theory?