Exactly, that's what I mean by "on rails". Imagine sliding a server PSU into place and it latches as it seats... do that but with a "GPU module". The case its

Exactly, that's what I mean by "on rails". Imagine sliding a server PSU into place and it latches as it seats... do that but with a "GPU module". The case itself needs to be part of the support to fix GPU sag, and that's only possible with dimensional and connectical standardization. Smaller stuff that still reflects the "add-in-card" intention of the original design is fine, you can still have a bunch of PCIe slots for network cards and USB controllers if you want. But the GPU is not really an "add-in-card" anymore and it's problematic in a design sense to keep acting like it is, let alone to have every single product on the market doing something completely different dimensionally. That's the "pre-USB-micro" era problem that USB faced. There's no need for water though, that's a whole can of worms.