We did agree on a definition intelligence! For 50 years, the Turing test was the unquestioned threshold beyond which machines would be considered "intelligent". The simple fact of the matter is that we've reached that point, but folks remain unimpressed, and so have set about moving the goalposts.
I am of the opinion that, when the dust settles, the point in time which will be selected as "the moment we achieved Artificial Intelligence", or even rudimentary AGI, will not be in the future, but in the past. This will be true because, once we take a step back, we'll remember that our definition of intelligence should not be so strict that it it excludes a significant percentage of the human population.
Consider this--is there any reasonable definition of intelligence which excludes Chat GPT 4.0, but which includes all human beings who fall in the bottom ~5% of IQ?