It's interesting you say 12 years ago -- 12 years ago was Leopard which according to Apple, contained over 300 changes / enhancements.
That is similar to Catalina with its too many new untested features.
Then they fixed the bugs in Snow Leopard.
The severity of Catalina's bugs are much greater than Snow Leopard. For example, there is now simultaneously a Mail deletion bug and iCloud bug to ruin your data across all machines.
System Preferences > Network > [click your ethernet or wifi adapter on left, unlock padlock if needed] > Click Advanced on right > Click TCP/IP tab > NONE, or Configure IPv6: Link-local only
That is similar to Catalina with its too many new untested features.
Then they fixed the bugs in Snow Leopard.
The severity of Catalina's bugs are much greater than Snow Leopard. For example, there is now simultaneously a Mail deletion bug and iCloud bug to ruin your data across all machines.
Catalina needs a Snow Catalina.