It depends on what you define as "good". I'm better than some but not as good as others. I don't do day game, or at least not in any significant quantity of approaches but get the occasional opener in. I do a bit of opening in bars and but mostly it is in social circle and Salsa bars.
I've been on the forum about 2 years but was an avid reader of the forum and GC articles for about a year before that which helped me improve:
-My understanding of women, what they find attractive, and more importantly what they don't find attractive.
-I dress much better and can read their body language so understand IOIs and can confidently open them and lead the conversation
-I can lead the interaction and understand setting frames which means they know what I'm offering and what my expectations are from them so if they don't like it they can move on. Interestingly most girls enjoy knowing what it is you expect rather than being a bland and leaving them guessing.
-I understand what I have to offer in terms of personal value and if they aren't buying into that then that's ok but I move on to someone who does value what I bring to them - I'm a little older so not every girls choice. But I can offer a great experience both in terms of a date and sex. (A date does not need to be expensive - but it does need to be a pleasurable experience.
-I can maintain tension, especially a sexual tension, and keep the interaction moving - where as I used to eject from interactions.
-I still need to work more on being seen as a lover and not get put in the boy friend box - that's my current work in progress.
Basically I have a lot more confidence in myself without being overtly pushy and am much more efficient at finding girls. I don't profess to be "good" but I am much more efficient and don't get hung up on any one girl, if she likes me great, if not I move on. I was away on holiday with friends a few weeks ago and was out every night with them. I had my choice of 3 or 4 different girls every night (not from our group) and I really wasn't trying, I was just leading conversations, deep diving, being interested and making them feel good about themselves.
So to answer your original question, it's taken about 3 years or so, I don't consider myself as PUA or particularly good, but I can run an interaction fairly smoothly.