Yes, there are projects where is paid to Ethereum but, as a rule, you will not earn much there. For me, it is more usual to receive tokens, because they have unlimited potential for growth and i can get much more profit.
In some cases it is true, especially if the project is really authentic, strong, and is already operational to so many consumers.
But most of them, the decline of price is so fast that you can't even have the time to send your tokens to that exchange.
So for some hunters here, just to be safe, they will choose projects that are paying either in btc or eth. At least, they have assurance that they will earn something every week.
But, I agree to others that sometimes if you're lucky enough, if you are in a good project paying their tokens, you will really earn money that it's almost equivalent to your one-year salary of a regular day job.
And one advantage of paying their tokens is really the movement in trading once it hit the exchanges, at least there are people who will activate the trading.
But, if the project really believe that they have something to offer in the community, that they have already sufficient funding for their developments, and that they really have money, then, they can run their campaigns via payment of eth or btc.
Or they can run both. They can get the advantages of both sides though.