We should consider building and shipping a source generator for equality as part of the default .NET tooling. The C# LDT has explicitly backed off from doing a completely-customizable equality feature: https://github.com/dotnet/csharplang/blob/master/meetings/2020/LDM-2020-03-30.md#value-equality. However, it seems like customizable equality (such as sequence equality for collections, case-insensitive comparison for strings, other customizations) are and will continue to be a pain point. We should consider building a first-party generator for equality, with annotation types built into the framework and the generator shipped with the SDK. If we don't do this with the initial release of source-generators or soon afterwards, we may end up with a fractured ecosystem of such generators with no consistent style.

/cc @chsienki