Unless you use server-side rendering or JS-only dependency, in which case you do need Node.js, its usage cannot be justified as it is a massive downgrade in every way vs .NET (ASP.NET Core + EF Core/Dapper combo).

Examples of major considerations are security vulnerabilities and dependency hell (both solved long ago in .NET), performance and memory footprint (the average expected difference in application code performance is >10x), and ability to reach performance ceiling with additional optimization, supported deployment targets, the quality of the languages themselves (C# and F#), interop with C/C++/Rust, IDE support, static typing, quality of the libraries in the ecosystem (fewer but much better), etc.