I’ll provide a different perspective. As a startup, your single focus in the early stage is to achieve P/M fit. If a SWOT analysis helps to conceptualize to you, who your customer is, what the problem you’re solving for that customer is etc, then yes, go ahead. But don’t do it just for the sake of having a SWOT analysis. Most startups don’t actually even understand the problem they are solving or have a clear value proposition (simply a number of hypothesis that they’re trying to prove or disprove). From that context a SWOT isn’t the most useful tool. After all, if you don’t know what your offering actually means to the customer (or don’t really understand who the customer is), how can you build a SWOT for it?