New to SEO - Semrush low KD < 10 easy to rank or where do I think wrong?

Hi, I'm relatively new to SEO, I'm just learning and testing all sorts of things, already had first small successes with my first clicks from google :) I am using Semrush and have now come across a keyword which has a total volume of about 1 million with variants. Semrush gives an average keyword difficulty of 9% with some keywords in the 2-6 range. I have researched other products of that kind (from the keyword) and found out that there are some with an average KD of maximum 15%. The SERP also shows that the competition often has no backlinks in the search results. As a beginner, I think I can position myself relatively easily with a little work to gain traffic even without backlinks. My plan would be to create a website for the keyword and start with affiliate links and then later build a website with the product myself. But it seems too simple to me, so not the implementation, I can manage that. I'm more wondering why it's so easy to rank for these keywords according to Semrush, what am I not considering? Unfortunately, as I said, I'm a beginner and would have to implement this plan to find out what my mistake is and would like to save a few hours with nice hints from you :D