Yeah, but that’s like answering “Oreos, Jaffa Cakes, Biscoff, could I theoretically bake my own cookies?” with “It’s a task that usually takes entire teams of highly competent and experienced people. Food scientists, industrial designers, supply chain management, factory design, lots of math”

Well, yes, but OP is not trying to make a product to compete with these examples. The answer is absolutely yes – to both cookies and file systems – and they can both be done in one afternoon.