Ryzen desktop chips use the same compute chiplets as server (server has a long tail for adoption and a steady need for replacement parts), so they have a large supply of chiplets that don’t meet server requirements but can be downclocked or given more voltage for desktop. This also fulfills the low end desktop market, so they don’t have to produce lower end chips on more expensive nodes. There’s also a lot of AM4 platforms that can get a new lease on life with a drop in Zen3 replacement.
Then you also have supply from the laptop side with similar issues (don’t meet voltage requirements for efficiency), which is where the APUs come from.
I think a big reason these companies are laying people off is because we actually did increase their taxes. The Tax Cuts and Jobs Act of 2017 (Trump’s only major legislation passed) changed the rules on R&D deductions after 2022 to balance the other cuts and allow Senate Republicans to pass the bill without a supermajority (through Reconciliation). This was meant to be a poison pill that everyone expected would get repealed before it went into effect, but efforts to repeal it fell apart.
https://pro.bloombergtax.com/brief/rd-tax-credit-and-deducting-rd-expenditures/
https://youtu.be/1ecu0YsCGxg?si=zh-39-HMHif-zvaU