.NET 10 is an LTS version, so it will be supported for 3 years, i.e. until November 2028. Like .NET 9, it doesn't bring anything that would radically change the way we write code. The only exception is perhaps C# 14, which finally brings extension members – a feature that was originally planned (under the name implicit extension types) to C# 13. The rest of the news is more of an evolution: faster JIT, post-quantum cryptography and more pleasant work with SDKs.
What is new in C# 14?
Extension members
We have known extension methods since C# 3. Until now, however, only a method can be an extension - not a property or a static member. This is now changing thanks to the new block extension: