I would love to here some MSFT people who work on the Net Core teams thoughts about these libraries, because it seems the community has really amazing things to contribute, such as this string builder library.

Net Core has seen amazing improvements compared to Framework, yet often still falls behind existing community offerings.

e.g. UTF8JSon library: https://michaelscodingspot.com/the-battle-of-c-to-json-seria...

Outperforms the new Net Core json library.

HyperLinq: https://medium.com/@antao.almada/netfabric-hyperlinq-zero-al...

Is basically Linq with 0 allocations.

What is blocking MS from integrating these approaches into Net Core?