The major point being missed here is all these guys running the game on a HDD + RTX 4090 also have >32GB RAM, meaning the game can cache lots of stuff to the RAM and VRAM during gameplay which hides the low I/O speeds.
But the thing is... who the fuck has 48, 64 or more GB of RAM, a graphics card with 24GB VRAM but then plays games on a HDD?
It's not a reallistic situation at all. The people gaming on HDDs are going to be using super low budget systems, graphics cards with 4GB, and system RAM at 16GB tops. And on those the HDD is going to completely break the gameplay with terrible stuttering and loading times everywhere because there's not enough volatile memory to cache into.
Also, the stupidest thing I read here was the claim that playing on a HDD was made possible thanks to DirectStorage.
DirectStorage only exists because the I/O got so much faster with NVMe storage. If we were still stuck on a 10-100MB/s I/O with terrible access times we wouldn't need to optimize data transfers in windows and find ways to do massive parallel decompression on GPUs. A single low end CPU core is enough to take an average 40MB/s data stream and do a 2:1 decompression to 80MB/s.
These people mistook Nixxes' excellent automatic resource allocation system with DirectStorage.