Ask HN: Early Stage Startup Product Advice

We are trying to figure out how to increase engagement on our website. In talking to our users that have created accounts, they always say that they are very interested in using our product and they are planning to use it but they have not yet because they are busy and don't have the time. Does that mean our product doesn't solve a strong enough problem? Is this a UI/UX issue? Product is similar to HackerRank. Help plz!