They see a lot more tourists than they did a few years ago, but it's still a relatively small number compared to other, more accessible tourist hotspots (about 2.5 million tourists per year, which is a lot on a country of only 340,000 people).
Especially if you visit outside the summer months then it should still be fairly quiet.
My visit was quite recent, from April 10th to April 20th, did see other tourists on my excursions, but no hordes or anything.
Most groups were at most a few dozen.
The hotels have gotten considerably more expensive (last time I went my hotel was €80 per night, now it was more like €180, same luxury level), but there was very little trash strewn around the locations I visited (and a few of those were definitely tourist hotspots, like the Golden Circle stops), so either they're very good about cleaning up after them, or people don't throw their shit around too much.