Minisforum does several things right:
1.) By default it is careful to populate both memory channels of the CPU with 2 DIMMS, thus giving a distinct performance boost for multi-threaded apps.
2.) It allows the users to upgrade the memory.
3.) It allows users to install 2x 2.5" HDDs or SSDs
4.) Primary disk is always user replacable NVMe.
5.) Factory disabled power saving features in the installed Windows OS and the BIOS. You always operate the mobile CPU at the peak power limit.
6.) Since it is a mobile CPU, it is as silent as a notebook.
7.) Really small box.
8.) Designed to connect several big external screens.
9.) Two Ethernet ports save the cost of an additional PC for more involved network setups.
10.) AMD GPU included with Ryzen CPUs, which beats Intel mobile GPUs.
11.) It is a "desktop PC" with notebook internals. It can cost less, because there is no need for expensive role resistant cages and the cooling solution can be somewhat bulkier.
With this approach, it easily beats most notebooks in performance, while allowing upgrades at the fraction of the cost of a comparable notebook. Unless you are an avid gamer, you dont need any other PC for most work. And you can still put the PC in to rucksack to go and visit your friend.
And of course, the plus points are what the competition is "not" doing. Go try build a 64GB RAM notebook with 16TB of SSD and see what the notebook costs.