My experience is that gear has not really got faster. Maybe by a small margin, but not by much.
I think what is driving those figures is:
- More people have got faster gear as they saw what was possible on that gear.
- More people have found and know about really good speed sailing spots and know when to go to them due to better being able to get good forecasts, and learning what conditions make it worth going.
Personally, the speed equipment I was using in 2006 is very much the same as what I use now. The board is the same one, my sails are easier to control, but very similar. My fins have not been improved on, except that in 2006 I sailed flat water behind a sandbar, with assy pointer fins, and now 98% of my speed sailing is using weed fins in shallow weedy spots. So arguably, my fins are not as fast, but the conditions I sail on are flatter, and the angles I can sail are much free'r. My fastest peak and 10 sec speeds were done between 2006 and 2013. Before the speed strip at Sandy Point deteriorated badly. I get flatter water and more speed sailing now, but most of it is at Lake George, South Australia, and it is quite rare to get the winds strong enough for me to approach my PB's at that venue.
So I would say that the overriding factor is still being able to get more wind at the ideal angle with flat water. It's that access and being in the right place at the right time on the right gear that is by far the biggest factor. Equipment advances far less so.

I am sure the same factors would apply in Europe.