I suspect it's Apple Silicon only because there are simple APIs that Apple has provided to take screenshots of the desktop and OCR text from images. I don't think OP necessarily built any low-level code from scratch here (not that their provided code isn't useful).

Someone else has previously looked into how Rewind.ai may be doing its thing under the hood and there are more details about it here: https://kevinchen.co/blog/rewind-ai-app-teardown/ OP may have used some of the info there.