In fact, Catalina doesn't have the newer accessibility problems that Big Sur has either. 13 Download Increased security 1/3 High Sierra is an update of MacOS.

I'm wary of upgrading to Monterey because I don't want new accessibility issues like busy busy busy on Safari, for example. 15 Catalina ISO File (Mediafire) System requirements for installing macOS Catalina. I also have the option of cloning my 2016 Macbook Pro to my slightly newer 2017 iMac Pro that has Big Sur on it, or vice versa, or I could just keep Big sur on the iMac Pro, or I could upgrade the iMac to Monterey.

As a rule of thumb, you should have abut 10-15 free space depending on the size of your drive. The reason I'm asking is that I know Big Sur, and I know Catalina, but I don't know Monterey, and I'm trying to decide whether to upgrade my 2016 Macbook Pro from Catalina to Big sur or to Monterey, or just stick with Catalina. While the OS may need state that it requires much space, you also have to consider that it needs more space to install and run. If you could choose all over again, now that you have experienced the good features and the accessibility bugs in each of these operating systems, which would you choose today? Monterey, Big Sur, or Catalina?

Upgrade high sierra to catalina