How do I downgrade to macOS Mojave from MacOS Catalina

My Suggestion here is to first reinstall the MacOS from Recovery and then followed by restoring files. Assuming you have good backup.

1. Support Article to help How to reinstall macOS from macOS Recovery https://support.apple.com/en-us/HT204904

• • Make sure step 2 is done (which is to erase <format> your disk)
  • Once you have done the above step macOS Recovery might offer only the macOS that came with your Mac, or the closest version still available.

2. Support Article to Restore from a Time Machine backup https://support.apple.com/en-in/HT203981#allfiles

• • Restore all your files with Migration Assistant.

This is one of the methods reverting to your previous macOS. If you or someone have better way to revert please follow that.

Please mention what major problem you have with Catalina apart from "no 32bit app support".

This would help other users to know what they are stepping into before they upgrade.