Even retired, Clint was a close friend with Wanda, or at least had a connection. His words convinced her in Avengers: Age of Ultron to join them against Ultron, he was sent to break her out of the Avengers compound in Captain America: Civil War (and she actually used her powers against Vision (!), though her feelings for Vision were just forming at the time), and she and Clint bonded at the end of Avengers: Endgame after Tony's funeral.
As you say, this was not a situation that called for science or smashing, but maybe needed a good friend. Of course, I doubt Darcy or Selvig knew of the bond between Clint and Wanda. Bruce might, but he was away for much of the above. Additionally, Clint is still dealing with his own issues at this time, but it would have been an interesting element to bring in.