Why installing OS on the M2 NVME SSD drive consume a lot of space compared to a regular 2.5" SSD

Hi,

I've managed to buy a used Dell Precision 7730.

It has 4 M2 SSD drives.

I've used the default USB to recover the original operating system for the machine which is windows 10 pro for workstations.

Also tried to install the Windows using the default regular way by getting a trial .ISO from Microsoft website and loaded it to a USB drive, and booted the machine from that USB and deploy the setup, but ended with almost the same consumed space.

After login I've been surprised that drive C which includes the OS, it is consuming 130 GB out of  459 GB!?

Any regular 2.5" SSD consume about 20~25 GB of space for windows 10 (what so ever the edition being used).

So, why installing the OS on NVME, or restore or recover the OS consume that much space with M2 NVME drive?