Going somewhat off-topic here but classic Mac OS had very precise human interface guidelines[1] which strongly emphasised repeatable behaviours and recognisable patterns. For that matter, so did earlier versions of Windows[2]. A lot of thought went into visual cues and design elements so that things looked and acted predictably system-wide and they were designed so that it would always be obvious which elements were and weren't interactive.

Both Apple and Microsoft have regressed in this respect. Minimalism and prettiness have taken priority over usability in both modern macOS and modern Windows and they are far more inconsistent and harder to learn to use as a result. Often something that you learn in one place place or app now doesn't work in another.

In Apple's case this has been mostly as a result of their efforts to make macOS and iOS more alike and to share applications/components across the two, which often creates weird-feeling results and awkward app designs. In Microsoft's case this is mostly because they have more UI frameworks than sense and each new one introduces more problems than solutions. Electron-adjacent apps probably don't help matters either, since they also generally break all of the platform rules and implement their own UI controls anyway.

[1] https://dl.acm.org/doi/pdf/10.5555/573097 [2] https://ics.uci.edu/~kobsa/courses/ICS104/course-notes/Micro...

That's the problem. For example modern MacOS has in your face notifications and allows applications in the background to steal focus.

I gather classic Mac OS was done so you can get on with whatever you're doing and nothing bothered you.

The Classic Mac OS Finder used a spatial metaphor. When Apple moved to OS X, they copied Windows by switching to a browser metaphor [1]. For many Classic fans this was Apple's biggest mistake. Ever since then people generally go out of their way to avoid using the Finder altogether because it's so unpredictable and opaque.

[1] https://arstechnica.com/gadgets/2003/04/finder/