The developer experience is a lot better for .net, in my opinion, but it’s also expensive and usually requires windows (yes, Linux .net is completely possible). Microsoft invests heavily into building better, easier tooling from end to end. If you are an azure shop, it’s very easy to deploy.
I haven’t looked at the latest benchmarks, but when I did, c# was a clear winner in performance, multithreading, etc. nodejs isn’t slow by any means, either.
Nodejs excels at speed of development and in BFF patterns like next or other SSG. .net will steer you into better design patterns for maintainability in the future. There are also more gotchas around nodejs which is mostly due to the funkiness of JavaScript.
It’s quite nice if you use nodejs backend and frontend. It’s one language and if you use typescript you can share types!
Bottom line, there are tradeoffs to both. I would be more concerned about your team composition, skill set, and project type when picking between them.
If you held a hun to my head, I’d pick .net