Comment by tbillington

vendor + linecount unfortunately doesn't represent an accurate number of what cargo-watch would actually use. It includes all platform specific code behind compile time toggles even though only one would be used at any particular time, and doesn't account for the code not included because the feature wasn't enabled. https://doc.rust-lang.org/cargo/reference/features.html

whether those factors impact how you view the result of linecount is subjective

also as one of the other commenters mentioned, cargo watch does more than just file watching