What’s one benefit of creating multiple ad groups?
- You can target specific ad groups into various Google networks
- You can break up keywords and ads into related themes
- You can set different budgets for each ad group
- You can pause specific keywords if they are not performing well
Well, maybe its not a misleading question, but still creates some confusion. A reason why you should break keywords into related themes, in fact, is to optimize your ads achieving better quality score and adjusting your bids. So, for me both answers “you can break up keywords ads into related themes” and “you can set different budgets for each ad group” are equally correct. Moreover, from my experience its a way better to have only one keyword with different matching types in a single ad group than having 5-10 keywords in one ad group as Google recommends. But its an another topic
Use ad groups to organize your ads by a common theme, such as the types of products or services you want to advertise.
Many advertisers find it helpful to base their ad groups on the sections or categories that appear on their website.
Read more here: https://support.google.com/adwords/answer/2375404?hl=en