Because there isn't a one size fits all solution to error handling? Because before anyhow/thiserror became popular there were 5 other popular crates for handli

Because there isn't a one size fits all solution to error handling? Because before anyhow/thiserror became popular there were 5 other popular crates for handling errors and if Rust added one of those to std we would be stuck with a subpar solution forever? Because cargo is so easy to use that your preferred error handling solution is one `cargo add` command away? Because for simple cases the tools the standard library offers are good enough?