The loss of the TSMC discount did not predate Gelsinger. TSMC pulled the discount directly in response to comments made by Gelsinger that they considered disrespectful and made it public knowledge. As I recall, there had been a rumor/leak around summer of 2024 that the board had been very unhappy about that.

While there were issues that predated Gelsinger, he did nothing to fix them. There is a great writeup on that here:

https://bcantrill.dtrace.org/2024/12/08/why-gelsinger-was-wr...

Pat Gelsinger was confident that Intel could keep doing things the way it always did for the most part and everything would be fine. That was in part due to government bailouts for its foundries under the false assumption that the US government would not consider TSMC or Samsung building foundries in the US to be an alternative to bailing out Intel.

Pat Gelsinger also killed the royal cores project which basically handed dominance in CPUs to AMD under the premise the future lied in GPUs. While he was not wrong to think that, that future involves GPUs made by another company and without leadership in CPUs to keep the company going, there would be no Intel. They reportedly lost their entire Oregon design team to a startup developing RISC-V processors as a result of that, giving them another competitor and putting another nail in Intel’s coffin.