Hmm. Seems like I had to go into Keychain Access > Certificates > Apple Worldwide Developer Relations Certificate Authority for one expiring in 2030 & change Trust to System Default. It was set to Always, and this fixed my issue.

~~Hmm. Seems like I had to go into Keychain Access > Certificates > Apple Worldwide Developer Relations Certificate Authority for one expiring in 2030 & change Trust to System Default. It was set to Always, and this fixed my issue. ~~

I believe this is entirely due to my company's Cylance Protect installation on my laptop. Many internal files have been quarantined and as such I cannot launch Xcode. I need my IT department to do something about Cylance so that I can get Xcode restored.