My question is how to avoid this in future. The latest update of Xcode (from 13.0 to 13.1) took nearly 24 hours to complete. The update was downloaded in a reasonable time, but the installation part took way too much time. I am running macOS Big Sur 11.6.1 on a 15-inch Mid 2014 Retina MacBook Pro. Although an old machine, a whole day to complete an update is ridiculous.
Ridiculous, in your view.
I would say, if such a modern application development environment can run on such an old computer, that is remarkable!
If Xcode runs at reasonable speed on a 2014 MacBook Pro, and is usable, then I am surprised, but good luck to you.
To speed up the installation in future:
How much resource does your MacBook Pro have? Storage? Memory? And the internet connection is stable enough while installing? Have you tried while Apple's server is seemingly free? It is quite usual it takes more than three hours to update Xcode, but have never heard nearly 24 hours.
I freed up about 80 GB of storage before the update. The Mac Book has 16 GB of RAM and the internet connection was stable (the update downloaded in proper time given my network conditions). I left it to the update only (Xcode was obviously closed during the period). I am somewhat expecting performance issues with such an old machine, even if the update took 6 hours, I would just shrug it off to the hardware being old. But for it to take nearly a whole day is another ball park entirely.