The Mac is a Broad family of computer systems with a WIDE range of performance abilities. MacBook Air is a somewhat less capable computer than the Mac Pro with ultra processor.
Historically, there have been certain versions of MacOS that changed things considerably. MacOS 10.15 Catalina, for example, eliminated the ability to run 32-bits only Apps, for example.
Running the latest MacOS is currently NOT a determiner of levels of performance. The latest MacOS does not contain boat-anchor features that will somehow drag down performance. You should always be running very nearly the latest version, to take advantage of features, and to have bugs already fixed, and make certain security issues have been found and fixed.