He was every bit as good this season scoring 28 as he was last season when he scored 44...
Things weren't exactly similar to the past few seasons, don't know if you noticed but a few things changed
Well I thought it was due him playing less games as it turns out its not (44 vs 43), so its obviously accurate to say his goals ratio per game has gone down.
Now admittedly some would say the fact that Juventus average between 70-80 league goals a season rather than the 100 odd Real Madrid might be a big part of that, and that's probably true, although that's still nearly half of what Messi scored this season, which is a huge difference. Remember Messi is 32 himself.
He is still playing for the best side in Italy who dominate that division more than Real Madrid have ever done in Spain at his time there.
You might geniunely be the one person on the planet that doesn't think Ronaldo's or anyone's longevity in the present is impressive. Your justification for it makes no sense at all.
Simply because sportsman of this era, on average are living longer in their respective sports than they used. This is not rocket science, have a look at Federer, Nadal, Djokovic and Serena Williams in tennis, which is a sport traditionally where being over 30 is a death sentence and all them are still extremely competitive if not dominating in that sport, when others previously never were. Tom Brady still the best quarterback at 42, which hitting 40 usually meant retirement. Tour de France winners more and more are in the 30s compared to previous era's where anybody over 30 in tour cycling was also near impossibility to win anything.
I'm not saying Ronaldo isn't partly responsible for his longevity, he clearly looks after himself and that obviously is helping him, nor will I ever question his incredible motivation and desire, but I do think he's benefiting from the era of much improved sports science however, I'm not sure he would be having the same longevity if he was a footballer in the 80s for example.
I think when we compare the longevity of footballers of his age group, you have to take into effect his level is/was so high to begin with that a moderate decline he is still going to be one of the top 10-15 players in the world, so he is still a great striker.
Given what I've seen in other sports, I'd be fascinated to see what happens with other big goal scorers like Messi, Aguero, Lewandowski who aren't to far behind him in terms of age, and we'll see how much of anomaly he is.
People used to salivate over Federer's longevity suggesting his rivals would never do what he did winning Grand Slams after 35+, but I always was skeptical of that as now seeing Nadal and Djokovic completely dominate that sport still at 32 and 33 confirms that having 3 tennis players dominate potentially well into their 30s plus Serena Williams in the womens game doing it is not a mere coincidence.
I personally don't think Ronaldo is potentially a stand alone miracle in this regard, Ibrahimovic admittedly is the only other world class striker who has Ronaldo like longevity (and I think Ibra went to the MLS too early IMO) but I do think some of his rivals behind him will be scoring plenty of goals for a while like he is.
That doesn't mean I don't find his longevity impressive, I do, but I think as I say its partly down to the era he is in that is certainly helping him.