Same here. The Java ecosystem has almost everything you could ever imagine needing so it’s a safer bet. Maybe it’s not as shiny but it works. I don’t understand why MS doesn’t provide the ability to call Java code from .NET. It would open up a lot of libraries to the platform. Right now there are a lot of libraries that are first class in Java but have either no or only half baked .NET ports.
There was some plan to beef up their Java Interop library (currently used with Xamarin on Android) for more general usage for .NET 5, but I think it fell by the wayside. It'll probably happen eventually though.
Not to mention projects like Apache Spark, Cassandra, Elasticsearch, Druid - Java projects. Many projects (Foundation DB, Scylla DB, I could find more) will have in-house support for Java and not .NET.
The .NET equivalents to these libraries tend to be playing catch up. Xamarin Android will always be playing catch-up to Android's Java/Kotlin APIs for Android. Big machine learning projects like PyTorch and TensorFlow tend to give first-class support of some fashion to a Java API (mostly due to Android). Is there a .NET equivalent to Deeplearning4j? Hadoop? Hive? Kakfa?
In Java there is a proliferation of web projects: Spring, Vert.x, Quarkus, Micronaut, Play 2, Spark Java; Netty, Jetty, Apache. In .NET all you ever hear about is Microsoft projects ASP.NET core; Kestrel, IIS.
Working as a .NET dev, when there is an SDK, if it's not from Microsoft, it's clear the .NET SDK is a lower priority for bug fixes and new features compared to e.g. the Java/Python/etc.
TensorFlow can run on any JVM for building, training and running machine learning models. They have created recently https://github.com/tensorflow/java
