Effectively it'd require the entirely memory controller and the cache, and scheduling. At point point you got most of the GPU w/ a stuck, non-programmable interface of a designated compute. Likely you'd never have to compete for advanced nodes as well.
I wonder what they’re doing with that hardware now.
Ethereum is designed to bottleneck on memory bandwidth (while being uncacheable) so at the end of the day the name of the game is how many memory channels can you slap onto a minimum-cost board. You won't drastically win on perf/w - but as mentioned by a sibling, 30-100% over a fully general-purpose gaming GPU is likely possible, because you don't have to have a whole general-purpose GPU sitting there idling (and it's not a coincidence that gaming GPUs were undervolted/etc to try and bring that power down - but you can't turn everything off). "ASIC-resistance" just means an ASIC is only 1-10x more efficient than a general-purpose device, so general-purpose hardware can still stay in the game. It doesn't mean ASIC-proof, you can still make ASICs and they still have at least some perf/w advantage.
However, if your ASIC costs $100 to get the same performance as a 3060 Ti, that's a huge win even if you only beat the perf/w by 50%. Particularly since your ASIC is likely way easier and more stable to deploy at scale, and doesn't require a host rig with at least a couple hundred bucks of computer gear to even turn on.
Only plebs were buying up GPUs from retailers or sniping websites, buying from ebay was for the chumpiest of chumps. Gangsters were buying them from the board partners a truckload at a time, true elites just pay someone to engineer an ASIC and do a small run of them. Eight-figures (as mentioned by a sibling) is plenty, a $50-75m run of ASICs is quite a lot of silicon even on a fairly modern node (and some mining companies were publicly known to be using TSMC 7nm and other very modern nodes). And when you invest that kind of money, you don't flash it around and scare the marks.