Lists Are 3 Times SLOWER in .NET 9!

Summary

This video highlights a significant performance regression in .NET 9 where `List.Add` operations can be up to three times slower than in .NET 8. While .NET 9 is in preview and being addressed, the core takeaway is the critical importance of performance testing your applications when migrating between .NET versions and across different operating systems to preemptively identify and mitigate potential slowdowns, especially when third-party libraries are involved.