If you don't know the first thing about keyword research, learn about it, then make sure you use this tool. It's by far the simplest tool I use in my keyword research arsenal. That's not to say the others are difficult to use, this one's just the easiest. If you aren't focusing on your site's SEO, then I suppose SEO research and a keyword like this may not suit you, but I believe that every business that has a website should focus on SEO - so a tool like this is a good tool to have.
Semrush's content and page optimisation tool is quite poor; it's not in the same bracket as Surfer. Frase is a good alternative from a cost perspective (if not paying the AI writing functions), it's cheaper, and Frase's keyword/topic heatmaps are quite unique. Sufer has a better UI and a shorter learning curve. It has an advantage in that it offers internal linking recommendations, which Frase lacks. Surfer also has limited competitor analysis (backlinks and page speed), which Frase does not. Both tools allow you to choose the number of competitors on the SERPS