The consumer version of chatgpt is very good at this if prompted correctly, as it can do a ton of web searches and compile results nicely.

If you're very early stage and you are not on an established market, your competitors may not be visible on google but are (almost guaranteed) on the same marketing channels as you are. For instance, if you sell accessories for cats, you and your competitors will be in the reddit / instagram / tiktok comments for relevant cat articles / videos.

Fun fact: On reddit, I found that a good strategy is to google search for users that are "advising" others for their "favorite" product. It's usually one or several guys astroturfing to get their product some social validation.