That misses the "vertically integrated" part. (As does everything else right now, which was my point.)

The thing you linked is just a regular Gigabyte-branded 5090 PCIe GPU card (that they produced first, for other purposes; and which does fit into a regular x16 PCIe slot in a standard ATX chassis), put into a (later-designed) custom eGPU enclosure. The eGPU box has some custom cooling [that replaces the card's usual cooling] and a nice little PSU — but this is not any more "designing the card around the idea it'll be used in an enclosure" than what you'd see if an aftermarket eGPU integrator built the same thing.

My point was rather that, if an OEM [that produces GPU cards] were to design one of their GPU cards specifically and only to be shipped inside an eGPU enclosure that was designed together with it — then you would probably get higher perf, with better thermals, at a better price(!), than you can get today from just buying standalone peripheral-card GPU (even with the cost of the eGPU enclosure and the rest of its components taken into account!)

Where by "designing the card and the enclosure together", that would look like:

- the card being this weird nonstandard-form-factor non-card-edged thing that won't fit into an ATX chassis or plug into a PCIe slot — its only means of computer connection would be via its Thunderbolt controller

- the eGPU chassis the card ships in, being the only chassis it'll comfortably live in

- the card being shaped less like a peripheral card and more like a motherboard, like the ones you see in embedded industrial GPU-SoC [e.g. automotive LiDAR] use-cases — spreading out the hottest components to ensure nothing blocks anything else in the airflow path

- the card/board being designed to expose additional water-cooling zones — where these zones would be pointless to expose on a peripheral card, as they'd be e.g. on the back of the card, where the required cooling block would jam up against the next card in the slot-array

...and so on.

It's the same logic that explains why those factory-sealed Samsung T-series external NVMe pucks can cost less than the equivalent amount of internal m.2 NVMe. With m.2 NVMe, you're not just forced into a specific form-factor (which may not be electrically or thermally optimal), but you're also constrained to a lowest-common-denominator assumption of deployment environment in terms of cooling — and yet you have to ensure that your chips stay stable in that environment over the long term. Which may require more-expensive chips, longer QC burn-in periods, etc.

But when you're shipping an appliance, the engineering tolerances are the tolerances of the board-and-chassis together. If the chassis of your little puck guarantees some level of cooling/heat-sinking, then you can cheap out on chips without increasing the RMA rate. And so on. This can (and often does) result in an overall-cheaper product, despite that product being an entire appliance vs. a bare component!