yeah this is 100% survivor bias; their success only means you can make money with already hugely successful & popular projects, it's not indicative that your project will be successful or that you're doing the right thing
but it’s an example of someone following through and bringing something to fruition, not to imply it means you’ll get the same sales and reception but working 15 years on a project is an insane extreme, if he can do that I can do a year or two just to say I finished it