You do realise there are other types of holiday than flying around the globe to lie by the pool in a country with cheap labour, right? I think I’ve taken like one return flight in the last 10 years (excluding work trips). My last holidays I’ve travelled to by train to other countries in Europe. My next holiday I’m travelling one way by train and one way by bike.
That’s not been my experience at all (also in Germany). Signal is super popular, especially with younger people (under 40). I don’t have a Whatsapp account and it’s super rare for it to be an issue.