Why my CPU and HDD is not working on 100% during extractions, installations and so on?

Let's assume your CPU is a dual core, with Hyper-threading, giving it 4 virtual cores [I know this isn't true, but bear with me.]

If you run a task that is single-threaded - simply, it can only do things serially, one part must finish before the next bit starts - then the maximum amount of CPU it can use is one core at a time. This is 25% 'busy' when looking at your total CPU time.
Now, the scheduler in your OS is a bit smarter than that, so it can shift tasks between cores to stop one getting all the fun & share the workload out a bit. It also isn't only doing that one job, your machine is running hundreds of tiny background tasks all the time, even if you personally are doing no work.

Long & short is that if a task is not a real CPU hog, demanding more & more parallel threads/tasks, it will only get one turn on the roundabout, it isn't going to get all the seats at once. This will limit how much work it can do at any given time & how 'busy' it will make the CPU. If it took the whole CPU, then everything else would grind to a halt.

The only kinds of task that get to sit in every available seat are things like video encoding & application compiling. These will make your machine sound like it's about to take off, as every single spare resource gets used up & the fans ramp up like a wind turbine. For more normal tasks, it's nice to be able to get some elbow room for other things you are busy with, and also keep your machine cooler & quieter when it really doesn't need the exercise.

Regarding your comment :

I saw higher % during playing games and when opening programs. I bought this SSD/M2 specially for faster operation, but its same like normal SSD. Any idea how I can get more from CPU?

Some games are very heavy resource users and the main use of an SSD for games is to reduce e.g. level load times or similar, where a large amount of file accesses are required.

Note you refer to "your HDD". It's an SSD - much faster than a HDD, which is a mechanical drive.

During normal play it is your GPU and CPU and main memory that are used. SSDs deliver max performance for serial access - e.g. large files, but random access time (lots of small files) would be a good deal slower (but still orders of magnitude faster than a HDD). Better SSDs also schedule multiple read ops to the best efficiency.

The random access speeds of your SSD would be between about 45 MB/s and 75 MB/s for tests using small files (but tests are not real world operations and expect a little lower in practice). The headline grabbing super-duper performance figures are for tests using sequential access to large files (i.e. easily predicted read patterns, one block after another that allow the SSD firmware to schedule operations efficiently). By comparison your SSD random access speeds can test at about twice that of a good SATA SSD of similar size. So it's still a good performance.

I'll finally point out that random access speeds of a HDD would be doing well to reach just 1 MB/s, so keep this in perspective.