I can see that one of the pods that we use Pendo is there in stack trace. I will try updating it to latest version and see if it fixes the problem

As seen in the spindump, Pendo was blocking the main thread. Updating it to latest version thankfully fixed this problem. PS: Pendo seems to use AsyncDisplayKit internally and there is a ticket for this there https://github.com/TextureGroup/Texture/issues/2029 Cheers!

MrtnFbg's answer inspired me to read more about redirections of streams. So I read about Linux STDOUT STDERR. In this specific case when I run this command, there is an output and there are some errors. Since I ran this command on terminal and on terminal the STDOUT and the STDERR is the console itself hence, I was seeing both the json and the errors. I now don't see an issue with the Xcode 13 or the command itself. I need to update the way I am consuming this command. Since I am interested only in the output of the command hence it should have been xcodebuild -list -json 2>/dev/null where I am redirecting 2(the error stream) to a file that just eats up whatever it gets(the /dev/null file)