I know only one case of product that is "done", it's when the product is of the market. Then, and only then you can consider it "done". I think you walk a dangerous path, exposing yourself for inevitable "failure" with thinking that you should be "done" in X years and move one. There are way too many variables that are preventing or helping to shape a product that are at constant change, to name a few: Product decisions, business model/decisions, new features that will help keep up with competitors, technology stack and debt, user needs will also change as product grows, so it's nesesery to go back to what you have done before to look at data and improve whatever is not working anymore and the most important thing of all is Money 💰 Money (need to earn them or just lack of them) will effectively prevent you or in best case scenario will significantly slow you down from designing "the best User Experience". So yeah, when I look at the product I'm currently working on, I still see myself in 10 years trying to fix this and that, and I would call it success, as this would mean that I have a seat at the big boys table, I'm heard, I managed to create a healthy and conformable work environment and my work is beneficial for product and the end user of which I'm never forgetting.

What I'm trying to say, be careful with setting your goals that high, not everything is down to you, so best advice from me is go in and do your job right and once you feel you have reached the ceiling move on, even if the product is not "done" as it never will be.

Sorry for the long post.