I get the sentiment, but 9/10 you won't actually understand the problem until you actually work on it. Work leads to understanding but understanding usually doesn't lead to work.

The counter to this are stories like Stripe. Collison has famously said they never would have started the company if they actually knew how hard the problem was when the started. They identified the problem and committed to solving it. But jumping in blind increased their chance of actually making something unique instead of just another credit card gateway.