It looks like C# and Java are now developed in parallel with the same features.
As someone who moved from Java to C# around 2013, I always felt that C# was close to Java but with less bad parts and more good parts. Looks like Java's now borrowing a lot of the nicer features which is good to see.
There are still so many nice exclusive features in C# that I definitely wouldn't want to go back to Java any time soon though (properties, powerful tuples, null coalescing, interpolated strings, ...).
Java needed string interpolation forever before _finally_ getting something. There are parts of C# that I think are going to look like a good idea at the time, but turned out not so great. Extension methods is one, and async/await is another. In fact, if Project Loom ever, finally, actually ships it'll make the whole c# code colouring thing look like the abomination that it is.
Java attributes and compiler plugins took their inspiration from .NET early version.
Default method interfaces in C# come from Java, LINQ vs streams, JIT / PGO caches,...
That is why it is still relatively easy to do consulting across both platforms.