Writing everything in C first is like building a house by forging your own nails. Yeah you learn a ton about how the metal works, but you're gonna be 60 before the roof is on. Your uncle's advice isn't wrong exactly, knowing what's happening under the hood makes you better at any language, but doing a whole semester of it as your default way to work is a waste of your time. Most real jobs out there are shipping Python or JavaScript or Go, and nobody's paying you to rewrite a REST API in C because it feels more pure. Learn C so you understand memory and pointers, then use it when you actually need it, like embedded stuff or drivers, not as some kind of purity test for every project.