Ok, so I figured out what it was. It was because I backed up (synced) my drive to the iCloud and apparently cloud-backed folders/files don't run in xCode.

@darkpaw - thanks for the quick reply. After reading your post, I deleted 13.4.1 and installed 14.1. Get Info does NOT have the "Open with Rosetta" checkbox marked. When I open my project's Runner, I get the "Loading" spinner, which has been running for 15 minutes so far (see image). Any other suggestions?