If you have a look at the German Velomobile forum (using Google translate} you'll get some idea of how things are in Germany and some surrounding nations. More dealers, certainly. Despite the name the forum caters for bikes, trikes and their electrified equivalents too. There is certainly more recumbent activity in Germany and the Netherlands than there is in the UK, for example. I suspect that recumbents are more popular in certain areas than others, depending on local terrain, nearby dealers or manufacturers and so on. Perhaps some countries never see a recumbent, while others with a manufacturing base are more likely to. The forum makes for an interesting read. Some recumbent names I'd never heard of.