Spinning off the foundry side would be bad for the tech world... though I understand why bean counters would want to do it.
Its pretty clear IFS can't be profitable on their own.. at least not at the leading edge. Which means they'd either go the glo flo route and step back to mature processes only or rely entirely on US government funding.
While IFS is a boat anchor currently, they are also Intel's best shot at regaining a competitive advantage. If Intel design is on the same TSMC node, and paying the same costs as AMD, ARM designers, RISC V designers, then i don't see where's there's room in the CPU market for them down the road. The other teams are just too efficient and agile compared to Intel.