How? The sublinks devs started the project just because they didn’t want to work on Lemmy for whatever reason. If they did, they would have worked on Lemmy. It’s either Lemmy AND Sublinks, or Just Lemmy with the same developers.

Having multiple implementations is a good thing, regardless of what language they use. They all implement the same protocol, should be (mostly) compatible, and can learn from (and compete with) each other.

Look at other OSS. There’s so many Linux distributions, Why doesn’t everyone just work on a single one?

Because everyone has a slightly different view on things. This makes the OSS community stronger.

I have seen people wanting to do Java, and while I personally prefer rust, I do see why.

Outside of the entire Sublinks discussion, it’s important to note that Java is not just Java anymore either. Kotlin offers many of the same advantages syntax-wise that Rust does (including the lack of null), and has access to Java’s excellent ecosystem.

Ultimately, it is up to people to decide what they want to use. Regarding of your opinions on Java or Rust, it is a valid choice either way for this type of software. It’s a personal choice.

Even if that were true - does it matter?

Java is a perfectly valid choice for something like this.

Yes, Rust is “faster”, uses less memory, etc…

Java is fast enough, though. It offers a fantastic ecosystem and, seeing as these projects are ran by volunteers who do this in their free time, there’s a lot more people willing to chip in some work.

They don’t because it’s not true.

There’s a few things moving to quarkus, but a lot of that is being pushed by Redhat (whose own software was not even spring boot but JEE)