It's probably because you're used to Rust and know how to write Rust in a way that just avoids all compiler errors. People new to the language try to write Rust code as if it were C++ or something (or, in general, are not yet used to the Rust way of doing things). I have had this issue with every language I've learned so far, most recently Go (which I tried writing as if it were Rust).

So often newcomers end up designing code in a way that at a higher level isn't too flexible when it comes to borrow check, leading to these issues.