I'm not so sure that the behaviours on one system are necessarily "better". I know that my preferences lie in one direction (away from MacOS), and I infer that yours lie in another. If a computer is a tool to get some set of things done, and these can be achieved with equivalent ease in systems which align to your preferences compared to the those which align with mine, then those preferences must be subjective.
Phones have a different pedigree -- I'm not upset if an app that's "open" is unloaded after some time or due to system pressure, even if I lose state on my phone, possibly because that's how things have always been (for a given value of "always"), and possibly also because phones don't have a dock or task bar to track "running" apps. On a computer, if the app windows being closed means the app is (mostly) unloaded and I will need to restore state with a new window, why not close it entirely? What does having it sitting in the dock with a dot consuming (admittedly few) resources give me beyond just pinning a shortcut?
Phones have a different pedigree -- I'm not upset if an app that's "open" is unloaded after some time or due to system pressure, even if I lose state on my phone, possibly because that's how things have always been (for a given value of "always"), and possibly also because phones don't have a dock or task bar to track "running" apps. On a computer, if the app windows being closed means the app is (mostly) unloaded and I will need to restore state with a new window, why not close it entirely? What does having it sitting in the dock with a dot consuming (admittedly few) resources give me beyond just pinning a shortcut?