[jmmv]

> * Non-human intermediate targets would either be namespaced and available only in that namespace, or could be marked as hidden, and not clutter auto-completion

This is actually possible but you need the new JetBrains-owned Bazel plugin _and_ you need to leverage visibility rules. The latter are something that's unique to Bazel (none of the other language-specific package managers I've touched upon in these replies offers it) and are even harder to explain to people somehow... because these only start making sense when you pass a certain codebase size / complexity.

> * I thought C/C++ rules would generate .o files, and only the final cc_shared_library would produce an .so file > * Similar for .jar files

These are possible too! Modern Bazel has finally pushed out all language-specific logic out of the core and into Starlark rules (and Buck2 has been doing this from the ground up). There is nothing preventing you from crafting your own build rules that behave in these specific ways.

In any case... as for dynamic libraries per target, I do not think what I described earlier is the default behavior in Bazel (we explicitly enable dynamic libraries to make remote caching more efficient), so maybe you can get what you want already by being careful with cc_shared_library and/or being careful about tagging individual cc_libraries as static/dynamic.

For Java, I've been tempted to write custom rules that do _not_ generate intermediate JARs at all. It's quite a bit of work though, so I haven't, but it could be done. BTW I'll actually be describing this problem in a BazelCon 2025 lighting talk :)