EMs are here to stay until the number of priests and deacons goes up.
And you, of course, are free to receive on the tongue every time you receive.
Perhaps they are, but they are not being used in accordance with An Instruction on Certain Questions Regarding the Collaboration of the Non-Ordained Faithful in the Sacred Ministry of the Priest, which specifically cites "habitual use of extraordinary ministers of Holy Communion" as something that is to be "avoided and eliminated."