> GC/runtime
1. Runtime: A runtime is any code that is not a direct result of compiling the program's code (i.e. it is used across different programs) that is linked, either statically or dynamically, into the executable. I remember that when I learnt C in the eighties, the book said that C isn't just a language but a rich runtime. Rust also has a rich runtime. It's true that you can write Rust in a mode without a runtime, but then you can barely even use strings, and most Rust programs use the runtime. What's different about Java (in the way it's most commonly used) isn't that it has a runtime, but that it relies on a JIT compiler included in the runtime. A JIT has pros and cons, but they're not a general feature of "a runtime".
2. GC: A garbage collector is any mechanism that automatically reuses a heap object's memory after it becomes unreachable. The two classic GC designs, reference counting and tracing, date back to the sixties, and have evolved in different ways. E.g. in the eighties and nineties there were GC designs where the compiler could either infer a non-escaping object's lifetime and statically insert a `free` or have the language track lifetimes ("regions", 1994) and have the compiler statically insert a `free` based on information annotated in the language. On the other hand, in the eighties Andrew Appel famously showed that moving tracing collectors "can be faster than stack allocation". So different GCs employ different combination of static inference and dynamic information on object reachability to optimise for different things, such as footprint or throughput. There are tradeoffs between having a GC or not, and they also exist between Rust (GC) and Zig (no GC), e.g. around arenas, but most tradeoffs are among the different GC algorithms. Java, Go, and Rust use very different GCs with different tradeoffs.
So the problem with using the terms "runtime" and "GC" colloquially as they're used today is not so much that it differs from the literature, but that it misses what the actual tradeoffs are. We can talk about the pros and cons of linking a runtime statically or dynamically, we can talk about the pros and cons of AOT vs. JIT compilation, and we can talk about the pros and cost of a refcounting/"static" GC algorithm vs a moving tracing algorithm, but talking in general about having a GC/runtime or not, even if these things mean something specific in the colloquial usage, is not very useful because it doesn't express the most relevant properties.