Germany is a very densely populated country. There are no big sunny deserted places. Also, 47+ degrees northern latitude... not great insolation (most of the CONUS territory is more southerly than that!).As an example, Germany subsidizes new installations with 12 cent/kWh. That is about three times the typical market price of electricity. In addition you are guaranteed that you can sell it - even if there is more production than demand on a sunny summer day. The government will still happily give you 12 cent/kWh for pushing electricity into a grid where the prices get negative, i.e. switching off your solar panels would actually be better for the grid. In addition you get some tax benefits and potentially local incentives for PV installations.
Sound great, right? Everyone must install PV like crazy! Well, turns out new installations have been dropping a lot over the recent years. New installations peaked in 2012 (when the subsidies were much higher than today), we are now below 20% of this peak.