If you're a poor responder or DOR, you may not get many more eggs with full stims than natural cycle. If you have qualms about making extra embryos, natural cycle only gets you 1, maybe 2, eggs per cycle. If cost is an issue, natural cycle is much cheaper.
But for most people that are normal responders, it makes sense to do stims and get as many eggs as possible. What is your diagnosis and why are you considering natural cycle?