No, we can't explain to you why our blub language should be preferred to your blub language. It's your job to make that determination on your own.
I can come back in 5 years to explain to you what is annoying about Akka.NET compared to the BEAM and vice versa. An expert in the BEAM who lacks experience in C# is not going to be able explain to an expert in C# who lacks experience in the BEAM why BEAM is better.
You're asking for something incredibly rare - a person who is an expert in both runtimes and can concisely explain to you the tradeoffs of each.
If you want to do exclusively distributed computing at the application level - Erlang/Elixir will be better. They can offer nice Northstar of where the UX of Akka.net/Orleans should sit at (and, arguably, Orleans is not exactly nice to use in comparison).
Otherwise, aside from educational purposes, they are not worth spending your time on. Just skip to F# over Elixir because Elixir is not a serious language, lacking base language primitives and operations one would expect standard library to offer. It's not productive nor fast.
With the latter I get a huge ecosystem of packages and wide compatibility with platforms and tooling and also a robust and scalable actor model.
Learning Erlang or any related language meanwhile feels like learning Tolkien’s Elvish for the purposes of international trade.