You over estimate the 'semi-pro' market for graphics cards. Gamers are barely willing to pay for 20GB. There's no market for consumer cards with an order of magnitude more RAM until games are built to use that memory.
A capable GPU with 24+ GB would sell if it significantly undercuts Nvidia. Just look at geohot building his tinyboxes with AMD cards.
Intel could very easily just put a buttload of VRAM on their existing GPUs to stick it to their competitors and make out like bandits. All they'd have to do is charge a Big markup instead of an Enterprise markup. And Intel has a better history of not making broken libraries.
What you are talking about is highly optimized inference using accelerators, batching and speculative decoding to achieve high throughout. Once you have that then compute is irrelevant except in terms of cost, but if all you have is a small consumer grade GPU you will be compute limited at the extreme limits of your context window.
I don't need long answers, I need by site specific knowledge base