I just have a simple NAS. That's about as crazy as I get.
Same... if you know tech and start considering building out a server cabinet like those pictured in the OP.... you wind up realizing you might as well just buy some space in AWS or Azure or another cloud.
Nothing wrong with building servers at home if you have real need for them, but it is expensive af to do it if you have nothing major to host.
Kinda like building a big flashy gaming tower only to run just solitaire and tetris.
Also for the OP... the pictures you posted reflect server builds... nothing specific to network/cyber security.
Network/Cyber security is something more ingrained in software/system engineering.... hardware plays a role, but I'd argue it generally takes a backseat to the rest of the landscape.
Would be like posting a bunch of pictures of walls and fencing and guard posts around an Embassy and thinking they represent "Embassy Security".
Embassy security is the people and processes/procedures they follow to keep the Embassy secure.
And yes they need walls and fences and guard posts, but those are pretty meaningless without the humans who utilize them.
Setting up a router or a switch or a NAS or a server rack or a UPS is all akin to putting up the fences and barbed wire.
The underlying software/firmware engineering, configuration, policies, etc are what wind up being meaningful to overall security.
