Intel claims to be able to ship 4 million this year, which is not absurdly low volume if they actually achieve that. It seems like a decent base volume as a practice run, as the intent was always for the next generations to become competitive.
And Intel has been poaching that talent. Also, Intel has been quite good at making deals with system builders, selling huge quantities of their CPUs to them in long term contracts, even when AMD had the better CPU's. They are well positioned to push their graphics cards into Dells and such, if they are half-way decent.
They explicitly say that they are only now trying to go for the prosumer market, rather than for iGPU solutions. Your claim seems to be that they've failed at something that they've not even been trying to do so far, which makes no sense. Of course Intel didn't manage to make inroads into the market for discrete GPU's when they were only selling iGPU's. That doesn't prove that they will fail if they actually try.
And I think that you fundamentally misunderstand Intel's strategy and why this is important to them. Their plan is to offer a portfolio of dies that can relatively quickly be combined into a multi-die chip and then to produce those chips. So companies like Google, Amazon, Tesla, etc will be able to order custom chips for general processing, AI, graphics, etc; or a specific combination of tasks, by picking dies from the portfolio and adding them together for a multi-die chip that matches their needs extremely well.
GPU dies have proven to be quite good for non-graphics tasks as well, so this is an important part of that portfolio. So I don't see them abandoning this unless they abandon their strategy, but they are spending huge money on implementing this. It's not just a whim.