From what I'm gathering, the biggest problem with Catalina isn't the switch to all 64-bit...https://www.macobserver.com/columns-opinions/dr-macs-rants-raves/wait-install-macos-catalina/
I've often done the macOS upgrade a little while after it shipped, mostly because I have to wait for some developers to catch up now that I use some music apps and plug-ins (before that, I'd jump right in most of the time). Catalina seems to be worse as some developers still haven't even posted they're working on it, and reports like the one above. There have been numerous iOS 13 issues as well that Apple has raced to fix. Hopefully these are bumps in the road for Apple and OS updates aren't always going to be like this.