I originally thought that too. A negative pressure case does not sound like it would work, but it surprisingly does. Minus the dust it’s alright (I personally clean my PC often to it’s fine with me). Yes it doesn’t have amazing thermal performance, but it’s average. It will get the job done on most builds. High end overclocked builds would be better off with one of those cases you mentioned, but for a midrange build it will fair well. Gamers Nexus did some testing on the H500 (which is the h510 with different front IO) and its gpu thermals we’re actually pretty good while the CPU thermals were “meh,” but acceptable.
TLDR: It won’t fry your system and it’s not a hotbox. It’s an average case for thermals.