A competant driver team.
The spun off company from chinas nvidia branch "Moore Threads" has a gpu out that you can buy, but drivers are extremely terrible on it.
Intel is an example of a major corporation who jumped into the dgpu game a few years ago, and they ran into several driver problems and still have many to this day.
The hardest part of gpu design nowadays isn't the hardware part, but the software side
of course, its just that its a huge task to undertake. People still give AMD shit for their drivers and they've been doing it for over a decade. It's a huge problem for any company to build a competent driver team, especially for graphics, be it on PC or on mobile (e.g Qualcomm has a negative stigma for not supporting its devices long). The when for it is not in any short time window and would be a task that would take several years realistically. One way to fast track it would be approaching in an open source way (e.g AMD/Intel linux GPU drivers) but at a corporate level, drivers for those kinds of gpus usually cost way more to produce (part of the reason why workstation and server gpus are magnitudes more expensive than their consumer counterpart)