For accommodation on german Caminos, it can also be very useful to bring a tent. I know it is an unpopular choice, but it can be a good solution here to lower cost and to have more flexibility and options. Especially in summer when the weather is nice.
Germany has a good network of excellent campsites with everything a pilgrim needs - hot showers, electricity to charge your phone, and often even washing machine, WIFI and restaurant / bar or "bread service" (you order in the evening and can pick up your fresh bread for breakfast the next morning at the check-in). Prices are similar to spanish albergue prices, usually around 12-15 Euros per night for one person with a small tent. Sometimes there are also small huts/cabins available for those who prefer a bed.
The Mosel Camino for example can be walked staying at official campsites (almost) every night. On the via coloniensis it was possible about half the time if I remember correctly, same for via imperii from Berlin to Leipzig.
If anyone wants to walk the Mosel Camino doing camping, I created a list of campsites from Cologne to Trier that I can share (haven't walked it yet, still planning, so it's only based on google search so far, but maybe can still be helpful).