Most of the time, you already know what needs to be done.
However, it takes careful planning and thorough consideration to put things into action. Even the idea of starting takes so much energy (physical and mental) that some people decide to put off plans instead.
I also noticed the problem of prioritization. Where often, you already know what needs to be done, but you don’t know how to order things in terms of prioritization. If that’s the case, you might want to consider classifying your tasks following the Eisenhower matrix.

This matrix helped me focus on what matters and do away with activities I can do without. And I hope this would help you too.
Yes, knowing what needs to be done is not enough. You also need to focus on focus on what’s important, not just urgent.