I think we humans commonly use the word “intelligence” as a placeholder for human-like ability to learn new skills, absorb new knowledge, process said information to filter/transform it, and the ability to apply it. It might help to distinguish effectiveness or usefulness from these capabilities - trees are effective in reproducing and useful perhaps, as are insects. But we wouldn’t consider them to be intelligent per my prior definition, unless you consider their species’ changes in response to selective pressure to be semantically similar to human intelligence. However such changes are passive not deliberate/active/intentional, and so I don’t count them as intelligence. Ultimately it’s just about our definition and semantics.