Mac Os eating more than 3.5 GB's of Ram:
I have seen windows and mac os taking about 3-4 GB of ram space even in cleaned PC with no apps opened.
Can't developers further optimise operating systems to eat less ram somewhat like other operating systems (like Lubuntu or many other linux distos) does?
Unused RAM is wasted RAM. OSes will often use as much RAM as possible for caching in order to speed things up, and they will release the RAM if you need it for running programs. There is no point in having the RAM and then not using it.
The OS is only using 1.11GB RAM [wired memory]. The rest is app memory. Chrome is a known memory hog, so try Safari instead, but that all looks pretty normal to me. Nothing at all to even bother about until that green bar on the left goes orange or red. It's barely used any swap either, which is quite surprising on an 8GB Mac.
BTW, learn & take to heart the modern adage "Empty memory is wasted memory." You want the OS to be as fast as possible. It does this by keeping things in RAM it thinks you may need again. This is a thousand times faster than fetching it from disk, even with modern solid state technology. If this cached RAM space is needed by another process, it will just drop it from memory to allow the new app to use it.
Of course, the reason a consumer-oriented desktop OS like macOS or Windows is bulkier than such as linux is the sheer quantity of 'user experience' features. If you really want an OS to be bare-bones, then you can sacrifice the 'ease' of use for a skinny stripped down version of nix that will do just as much… but won't help you out as a newbie. It will make you research every function, then type it in, in Terminal. Many modern nixes don't go all the way down to this, they also have some 'user comfort' added.
Since Vista Business (Pro) (Windows) 64-bit 15years ago, 64-bit systems (All Windows, and as far as I know, Mac) take a basic 4 GB (+-) to run.
The address space for a 32-bit workstation only allowed 3 GB (+-) and 64-bit allows a much larger address space for bigger applications. 4 GB has always worked decently (for me) since that time.
Memory is inexpensive, so just outfit your machine with 8 GB of memory (or more) and that will definitely alleviate your issue.
Since much runs in the basic 4 GB space, there does not seem to a basic drive to reduce the memory requirement.
Memory usage in a modern OS is highly optimized. That is the OS tries to make the most efficient use of available memory. But efficient use of memory does not mean using less.
The old idea of memory use was that memory was a precious resource that should be used as sparingly as possible. That was necessary in old operating systems running on hardware with limited resources. That was the case even on mainframes through the 1950's.
But in the late 1950's the idea of a virtual memory OS was introduced. Note that virtual memory does not mean pagefile or swapfile. There is much more to it than that. This idea was further developed during the 1960's and by the end of the decade it was generally regarded as superior to other memory management systems. That remains true in 2022. This is for general purpose operating systems, not those for specialized needs.
Small computer systems, the kind that would be used by a home or small business, generally did not have the hardware resources needed for a modern virtual memory OS until the 1990's. By the dawn of the 21st century Windows, Linux, and the Mac all had a form of a virtual memory OS. This includes smartphones as well.
In such a system memory is recognized as the fastest storage medium and thus should be used to the fullest possible extent. Free memory is the ultimate in wasted memory memory, something that should be avoided if at all possible. The ideal would be zero free memory at all times, but we aren't there yet.
Memory usage in a modern OS is highly dynamic. The OS memory manager controls how much memory a process can have and how long it can keep it. The goal is always to optimize overall system performance, not to minimize memory usage. When there is no memory pressure processes are allowed pretty much whatever memory they want with few restrictions. This is best for performance.
But when memory pressure increases the OS makes some adjustments. The memory usage of processes is trimmed back to meet the increased demand. A modern OS also has several forms of cache whose size and contents are adjusted according to need and memory availability. All of this is done totally transparent to applications. The memory usage of an application on the same computer doing the same thing can vary by a factor of 10 or more depending on memory pressure. And all completely normal.
The computer in the screenshot appears to be operating normally as was designed. Unfortunately the principles used are not well understood by most computer users and that often leads to confusion.
