Recently, there were two new features merged in .NET 10 I think are small little quality of life improvements: Avoid Blocking on startup with BackgroundServices and a new string comparer.
LINQ has a Join operator, that basically translates to something like a SQL INNER JOIN. There is no built in operator for a LEFT JOIN in LINQ, but you can achieve the same result by using a combination of GroupJoin, SelectMany and DefaultIfEmpty. But there is a chance that this might change in the future, as there is a proposal to add a LeftJoin operator in .net 10.