The main benefit for Google Ads is to understand what competitors are in the space, what creatives they are running, and what keywords they are targeting. On this last point you may discover keyword themes you haven’t thought of yet for your campaign.

Of course there are other tools such as keyword planner, ChatGPT, Google’s transparency tool that get you most of this information. The main feature of SEMrush is competitor identification if you don’t already know who they are.