10 years ago I remember adding a project reference to share code between some C# projects by right clicking and picking add reference. Took about 5 seconds. Here I am, 2021, and doing the same thing in Typescript is apparently a nightmare.
Every time I find something nice about nodejs, I find something else that pisses me off to no end.

Ditch nodejs, JS, TS etc.

Blazor FTW !

It's probably very easy, but because the Node ecosystem has 4 different tools for each purpose it has to be done differently every time. Your best bet is to create a module (you can link local modules and git repos as well if you don't want to use a package repository) and configure your toolchain to build for UMD. The procedure for that depends entirely on your toolchain and things like which libs you want to bundle with it and which you want the external environment to provide.

All the complexity in the Node ecosystem derives directly from its openness and youth. C# is convenient because a single actor - Microsoft - gets to decide everything.

I'm not sure openness has much to do with it. I said C#, but other languages have similarly simple mechanisms.

@NoToJavaScript web assembly looks awesome but I'm too deep into node already. Maybe I can consider it for some smaller application later, though the lack of IE11 support might be a deal breaker for some clients.

Node js is a pretty whore who the closer you look at the more scabies you realize it’s infected with
I finished for the most part my one and only project in that language to the point where it did what I wanted and now I’m done with that shit lol

Bout the only thing it’s good for is web services and electron