Well, requests is a third party library. I don't like Python's standard library's HTTP APIs. I think that's a common sentiment. Similarly, you can get a solid third party its client for dotnet [1]. .NET core certainly has its shortcomings. I'm going to rattle of a list of other high quality libraries that address the .NET core shortcomings for me personally:
1) Dapper - https://github.com/StackExchange/Dapper
2) DbUp - https://dbup.readthedocs.io/en/latest/
3) Autofac - https://autofac.org/
The Kestrel source code expanded my view of what was possible in C# with respect to low level operations on memory (check out the fixed statement [2]).
A part of me doesn't want to like Microsoft because of their anti-competitive behavior in the past and crappy developer experiences from 10 years ago. Now, I sound like a Microsoft shill because of how good .NET core is.
[1] https://github.com/restsharp/RestSharp
[2] https://docs.microsoft.com/en-us/dotnet/csharp/language-refe...