Intel needs expertise that only a few hundred people on Earth have, and most of them are in Taiwan, already working for someone else.
You don't just buy an EUV and start printing, you buy an EUV and give it to a wizard to use as a wand. Intel needs wizards.
Their latest node 18A is already in production and should be a lot closer to TSMC's latest and greatest, with the first products shipping early next year.
This is something I don't understand. These companies make good profits -- why don't they pay their experts well?
They don’t make good profits. TSMC has fairly mediocre numbers by the standard of the tech industry. Intel has really bad numbers for the last several decades. AMD was having so much trouble with foundries that they spun it off.
That is actually a big part of how TSMC got ahead. It's a race. All those years of being able to get PhDs to work midnight-8am (because you're the most prestigious employer in the country, by far) move you to the next node just a bit faster. It adds up.
Why work smarter or harder? Do both!
TSMC's market cap is US$ 1.560 Trillion
It turns out when you are manufacturing nvidia's GPUs, Google's TPUs, AMD's CPUs and GPUs, Apple's processors, and the flagship smartphone chips from Qualcomm, MediaTek and Broadcom - and none of them can go elsewhere because your products are so far ahead of the competitors - that's pretty valuable.
Convincing TSMC to sell you their chipmaking trade secrets? You might as well try to convince Apple to sell you their smartphone division.
None of this stuff is published (externally) and there are no discussion forums or stack overflows to help you either. You need to get through academia, prove yourself, and then you can start working on a chance to get access to the trade secrets that make it possible.
After all that you will be placed as a researcher on a handful of steps in the multi-thousand step process of making SOTA wafers. And probably not make crazy money, but at this point, you're not in it for the money anyway.
It's important to note that it wasn't always like this. Up until the mid-90s this stuff was all published in the open literature fairly quickly.
There has been a steady culture shift towards ultrasecrecy since then.