Needing everything to be a class
In 2015 they added scripting. If you're making a real project, you should absolutely use classes. (It's not that hard. Don't do the Java shit.) But you can absolutely write one off scripts just fine.
AOT support is still lacking.
Publishing your app as Native AOT produces an app that's self-contained and that has been ahead-of-time (AOT) compiled to native code. Source.
Blockchain is effectively a distributed database. Almost always a good centralized database functions better.