Please give me current perspectives/strategies on churning a MileagePlus credit card.

About the Card: It was opened in July 2017 and has a $7k CL. My reasons for having it are threefold: Free bags. Better availability of award flights. And boarding priority. However, I don't fly UA much anymore so I don't need the card, and I don't care about earning MP points, except for a SUB.

About Me: I'm at 2/24. I have $150+k available credit. My annual income exceeds that amount. Average credit age is 12 years. (Three cards are 30+ years old.) My credit use never exceeds 2%. All balances are paid in full. My FICO is 808.