Not sure that Fuerteventura was lucrative for Ryanair otherwise it would not have pulled out when the airport refused to accede to demands. It would not make sense for Easyjet to fly to Tenerife 5 and 7 times a week in the Summer and then to pull out in the winter which is peak season for the Canaries. It's not as if there are other obvious leisure destinations to fly to instead during the winter.