I agree it takes time to do it the right way, but you cannot know about "Years", maybe 18 months, Because i follow allot of websites, and i see the results, and also this field (SEO, google updates) Is very dynamic and relatively new, so there are allot of changes and algorithm updates in one...
Can take week, or 5 months :)
In different languages than English, sometimes google updates are very slow so you may see spammy websites.
And sometimes google updates go "Wrong" in a way that can be good for you, and rank new website very high for few days, than it's important that the website...