For this feature though they’ve tried to select the topics to be ones that “[do] not include sensitive categories (i.e. race, sexual orientation, religion, etc.)”. The list is also public and gambling is not on it:

https://github.com/patcg-individual-drafts/topics/blob/main/taxonomy_v2.md

While this won’t satisfy those who want no individualized ads or no ads at all, it would be an improvement over what we have now and put control over what topics are used (or even if it’s enabled at all) in the local browser instead of some server online.