Having worked in the semiconductor industry, manufacturing specifically, I can attest that this is a false statement - US technology in semiconductor manufacturing is not simply from running the fabs, but building fabrication equiment that fabs purchase to process and package wafers. The US (Teredyn, Applied Materials, Entegris, KLA Tencor, Lam Research), Netherlands (ASML) and Japan (Daifuku, Hitachi, TEL, Advantest) are the top leaders of the semiconductor equipment [1]. The ones I just listed account for over 90% of the semiconductor equipment.
Most of the deep tech in a fab is the equipment. The rest of the stuff is a giant box that's super clean and maintains that clealiness.
All of these Fabs[2] buy their equipment from the aforementioned companies.
Here is what an example supply chain looks like:
NVidia(US) has the IP and "soft" tech, they use software tooling(US) to make layouts, then contracts out the manufacturing to TSMC(Taiwan) who then buys their equipment from KLA/AMAT/LAM/TEL/ASML. TSMC(Taiwan) processes the wafers which are packaged at OSATS(OSATS are a collection of many companies[3]). The final product such as a graphics card is then further made accessible by writing insanely deep software driver stack (CUDA drivers for example) that are all developed by NVIDIA(US). For CPUs, there would be ISA and other "soft" tech involved which is Intel(US), AMD (US), ARM(UK, owned by Softbank(Japan)), Qualcomm, Broadcom, Microchip and Apple (all US, its a long list). I didn't even touch storage/memory. In addition to US, a lot of software and hardware talent and manufacturing comes from the EU, Germany in particular. I used to get on the call with a German company in the late morning and the Germans would be working their ass off at 9pm in Germany. We had an amazing team. It is not uncommon to pay $20k for a motor made in germany.
Somewhere in the middle to low end of the supply chain (motors, wires, connectors, may be even steel, copper, precious metals, chemicals) probably has Chinese involvement. You can imagine how a graphics card's supply chain gets very complex and deep.
Back to the central point - Semiconductor is a massive industry with complex supply chain. Depends on the level we are talking about. Also Global Foundries is not considered as among top dogs when it comes to semicon tech, although that's also debatable.
Edit: added tooling
[1] Source of the data (2011, old but still relevant): https://www.vlsiresearch.com/public/cms_pdf_upload/706001v1....
[2] https://en.wikipedia.org/wiki/List_of_semiconductor_fabricat...
[3] https://en.wikipedia.org/wiki/Integrated_device_manufacturer