I worked in Indesign 16.0.1 without any troubles since last thuesday:
Opening indesign took forever. After a restart of the Mac, and 2 cups of coffee, i could finally work in Indesign without further troubles.
Today, Indesign starts but after 20 sec. or so, it hangs. It does not matter if it is a empty new file or a file with links and fonts.
I uninstalled indesign, restarted the mac, deleted possible corrupted fonts, updated the mac system, installed indesign again..... same problem. It would not start! So again, uninstalled, deleted caches, recoverd SSD (https://support.apple.com/nl-nl/guide/disk-utility/dskutl1040/mac), installed indesign and restarted the Mac. Indesign still hangst directly after starting.
So again... uninstalled, deleted cache and all indesign preferences etc, installed an old version (15.1.3). AND IT WORKS!
the whole shabang took 3 hours, and now i'm working in an old Indesign version.. I def wanna try to make the latest version work, but dont want to spend another 3 hours figuring out how. Why is the latest version suddently not working anymore and how can i make it work again?
Sorry to hear about your experience. Would you mind sharing the version of the macOS? Did you use Creative Cloud Cleaner tool to uninstall the app? If not, you may try this & reinstall InDesign once done.