It can be beneficial to group similar keywords together in the same campaign or ad group, as it can help you manage your bids and budgets more effectively. It can also help ensure that your ads are showing to the right audience for those specific keywords.
In your case, since the search terms "rubbish removal", "rubbish removal near me", and "rubbish removal Washington" are all related to the same service, it may be helpful to group them together in the same campaign or ad group. This way, you can ensure that your ads are showing to the right audience for all of these related search terms, and you can manage your bids and budgets more effectively across these keywords.
However, you should also keep in mind that each keyword can have different search volumes, competition levels, and performance metrics, so it may be helpful to create separate ad groups within the same campaign for each keyword to allow you to set specific bids and budgets for each one. You can also use negative keywords to ensure that your ads are not showing for irrelevant search terms, which can help improve your ad relevance and reduce your overall costs.
Overall, the best approach will depend on your specific goals and performance metrics, so it may be helpful to experiment with different campaign and ad group structures and analyze the results to determine what works best for your business.