I disagree. It’s likely they go about almost all their day-to-day activities using proprietary (or at least not libre) software. Their primary OS (likely Windows or Mac), word processor, spreadsheets, presentations (Office or Google), email client, virtually every app on their phone (either platform). If they are in any non-CS, technical field, it is for sure using proprietary software (MATLAB, Autodesk, Adobe, ...). If they are in CS or a dev, they are probably using cloud platforms, GitHub, CI, an IDE, ...
Programming languages and code are so unique in being freely available, even the infrastructure around the them is proprietary.