I prefer 1 hour/1 day/etc but yes, this is the only method that I’ve found to work. Be very clear what result you’re trying to produce, spec out the idea in detail, break down the spec into logical steps, use orders of magnitude to break down each step. There’s your estimate. If you can’t break it down enough to get into the 1 day/1 week range per step, you don’t actually have a plan and can’t produce a realistic estimate