Star imports aren't the only way, traits are another. Say you impl two traits and they end up both adding a symbol with the same name. Or you bring in an extens

Star imports aren't the only way, traits are another. Say you impl two traits and they end up both adding a symbol with the same name. Or you bring in an extension trait impl for a standard library type, and now the standard library adds a symbol with the same name as one in the extension trait. To avoid those problems, you'd have to proactively disambiguate any item with its trait name, which is so un-ergonomic that people genuinely prefer the possibility of occasional breakage.