Isn't VSCode with Copilot (or even with Intellisense) a "syntax-directed" editor in modern terms? Those tools are helpful precisely because they understand the AST of the underlying language. They can often suggest correct code that should come next. And they're wildly popular.
Syntax directed editors often limited what you type to valid syntax and automatically provided appropriate indentation. There is less freedom while editing as a result.
Problems come when you want to violate the rules of the grammar. Perhaps you want to use a recent syntactic construct in the language not yet supported by the editor. Or perhaps certain escape sequences and/or quotation marks confuses the editor.
Am I missing something?