Analysis paralysis is a mental loop where a person becomes caught up analyzing a problem over and over again without ever solving it. They dig deep into the pros and cons, they rephrase the problem, they look for different problems to replace it, they repeat the same steps over and over again, dissect existence itself to find more options... They become obsessed with the cerebral experience of planning for how to solve the problem at the expense of actually doing so. This is not a conscious decision anyone makes, but rather, a protective mechanism from the subconscious (https://lib.hol.ink/index.php?topic=50).
Analysis paralysis is often triggered by the paradox of choice (https://lib.hol.ink/index.php?topic=46).
It can be especially bad when there are too many options to realistically account for every possible combination of solutions, their relationships to the surrounding problems, etc. The designer may be in a tight / low-scope mindset where they feel that level of detail is necessary, but the large scope of the options simply doesn't allow them to apply it, and they become too overwhelmed as a result. Learning to shift between differently scoped mindsets, finding a framework to group the options into logical sets, or reducing the options to only the most relevant ones with data validation (https://lib.hol.ink/index.php?topic=34.0) techniques can help here.
Analysis paralysis can also be influenced by a fear of failure or risk-aversion. The reality is that we often need to make a decision without all of the information. Someone has to make the final call and then deal with the fallout if it turned out to be the wrong one, and that is a scary thing to acknowledge. It's understandable to not want to step up to that plate. But if you are in a position in a project where that is your responsibilty, putting it off won't change that; it just tightens the deadlines for everyone else who is waiting on your step of the job to start theirs.
Sometimes, you will simply need to gather the data afterwards based on how well something worked in practice. There won't be enough data or enough time to be certain beforehand. And in those cases, there is a high chance of failure. There is a lot of risk. Thankfully, in art, these risks are usually not matters of life-threatening stakes the way they are in, say, heathcare or finance. We may just need to find some way to reframe them to overcome the mental hurdles trapping us in analysis paralysis.