Socket HttpHandler is the default implementation in .NET Core 2.1. SocketsHttpHandler class provides the implementation used by higher-level HTTP networking classes such as HttpClient.
Based on my research, I don't think this change is necessary. Using HttpClientHandler on .NET Core 2.1 and later actually uses SocketsHttpHandler under the hood, unless overridden using an AppContext setting or environment variable. So we can continue to reference HttpClientHandler and get all the benefits of SocketsHttpHandler on platforms which support it, while still providing users with an option to fallback to legacy.
Socket HttpHandler is the default implementation in .NET Core 2.1. SocketsHttpHandler class provides the implementation used by higher-level HTTP networking classes such as HttpClient.
Benefits
Significant Performance Improvement.
Consistent behavior across all .NET Platforms
Can specify ConnectionTimeout