Is it worth migrating Dotnet Standard 2.1 to .Net 6 in specified scenario

Question

Scenario:

I am planning to upgrade a WebApi-based web project from .Net 5 to 6. I have many dotnet standard 2.1 class library projects in my solution. When trying to upgrade from EF Core 5 to 6 it did not allow me to do so. Error says

Package Microsoft.EntityFrameworkCore 6.0.0 is not compatible with netstandard2.1 (.NETStandard,Version=v2.1). 
Package Microsoft.EntityFrameworkCore 6.0.0 supports: net6.0 (.NETCoreApp,Version=v6.0)

Questions:

Should I migrate all my class libraries to .NET 6.0?

Is it worth doing it?

Am I losing anything just to get the latest EF Core?

Why dotnet standard 2.1 support is not recommended any more?

Answer 1

There is a great article detailing why .NET team has decided to move from .NET Standard approach - The future of .NET Standard:

Problems with .NET Standard .NET Standard has made it much easier to create libraries that work on all .NET platforms. But there are still three problems with .NET Standard:

• It versions slowly, which means you can’t easily use the latest features.
• It needs a decoder ring to map versions to .NET implementations.
• It exposes platform-specific features, which means you can’t statically validate whether your code is truly portable.

To your questions:

Should I migrate all my class libraries to .NET 6.0? Is it worth doing it?

If you are going to maintain and/or develop the project further it is totally worth it. .NET 5 is out of support now and will not receive any updates including security ones

Am I losing anything just to get the latest EF Core?

You are not only getting the latest EF Core. You are getting a lot of other stuff too - aforementioned security updates, performance improvements, new language features. As for loses - the main one would be ability to use your libraries in .NET 5 projects but it can be solved with multitargeting, but based on the question I doubt that you will actually need it.

Note that .NET Standard is not deprecated and the following frameworks versions should support it (so you can use .NET Standard libraries in them).

Read also:

• .NET Standard overview
• .NET and .NET Core Support Policy