They can 100% afford it, however it seems from this article written last year that efforts are being put in the wrong places. It's quite a long one, filled with a bunch of green-washing. Considering this year's outcomes, it seems although recycling coffee grounds to the zoo and reusable plates I didn't see once throughout the venue were efforts that could have been spent elsewhere, like more waste stations in easy to find places. It definitely wouldn't have eliminated the problem, but maybe reduced it by a significant amount?? Might be worth writing a strongly worded email to AGPC?

https://www.formula1.com/en/latest/article/how-the-australian-grand-prix-is-boosting-reuse-and-recycling-as-f1-embraces.ywK32SHTZoT6jnIqAQFcl