How do I know if a product is a good idea to pursue? i will not promote

I have an idea in a field that has little-to-no competitors (only 1 major brand in the UK) and I need help figuring out if I should continue on with the idea or not. It is a vastly prevalent issue, but I did a survey asking if people would be interested in purchasing a product like this one and 6/8 replies to my survey said no. Now I know that this is still an extremely small sample size for a survey to make an educated opinion, but I still have concerns. The other brand who is also doing this idea (similar but not exactly the same as mine) seems to be doing well, and has over 50K followers on instagram, indicating that there is potential for this product to work if designed and marketed correctly. Anyone have any advice? Should I keep trying to survey some more? I've read online about asking friends and family about their opinions but I want to get objective and non-biased responses, and these friends and family aren't exactly the target audience. TLDR: How do I know if i should pursue this product venture. Only 1 other major brand in this field, which seems to be successful so I feel like it could work. Looking for advice. i will not promote