RecoveryOS not working as expected after Big Sur

I am not liking much Big Sur so I wanted to move back to Catalina. I am using Shift+Option+Command+R, which, I believe, will install macOS which came in with the MacBook. However, I see the RecoveryOS but it gives the option to Reinstall macOS Big Sur. It leaves me with only one option and that is to reinstall Big Sur again.

Previously, when having Catalina, this option was not specifying any OS version. What OS is installed depended on what key-combination was used to boot into RecoveryOS.

Please help me to go back to Catalina. Thanks.