this might not be exact case, there are a few variants now
That case has the "front" intake on side of the case, so that air blows in and bounces off the glass and then gets sucked out top
the 3 intakes on bottom feed his 3070 and make sure hot air doesn't gather under GPU, and gets blown up into the 3 exhaust fans on roof.
I assume his AIO is mounted in roof. Might not cook CPU too much compared to people I seen with similar setups but with 3090
More intake than exhaust creates positive air flow and means no heat will linger in case as it will get blown out. Also good for dust management provided intakes have filters on them
positive - more in than out, means dust only tries to get in through fans, all the extra air blows out anywhere it can
negative - more out than in. Can mean dust tries to get in where even there are holes in case
Balanced - hard to achieve
I currently have negative and only spot I ever see any dust is on my top exhaust fan filters but thats more a flaw of my case design and me having too much exhaust - I could remove filters but then dust falls into case. Easier to just clean top of case every month. I have intended to unplug one of my exhausts but its not happened yet.
My last pc case was designed with positive in mind, 3 x 180mm intake fans, only 1 120mm out. Air had no where to go but out. Its still rated as one of the best Air cooling cases on Gamers Nexus, makes the new ones look like fish tanks with rgb - oh wait, many are. Even my new one is.
My old case has same internal design as this one
SO I totally know how good positive can be