I may think that's another way exchange adding some funds for their company. It's all about business. In the other side, we can't say it has no function. It has the same function in all exchanges, to be utility token where you can get benefit for holding them while using the exchanges services.
Of course, what you said is right, but we should be careful with some of the exchanges out there, most of the exchanges using their token as a utility token and it will help the customers to trader there, they will collect the fee in the form of their utility token. Exchanges will create their own token because this will help them to get more awareness about the project.
It not about awareness but rather it does have several reasons like on making more money and of course with that exposure you've been talking on.
There are exchangers who doesnt have their own dedicated token though but since we do talk into those who does have then they are going into different path
but doesnt mean that these coins are bad for you to consider on making it an investment because you wouldnt know if that exchange would succeed or not.