Same as everywhere I'd say - bitcoin works just fine... But if you wan't to spend in daily life, you'll need one of those crypto credit cards and some few locations in major cities that may accept payments when the right person is behind the counter. 5/10 people still laugh when I mention bitcoin, 4 will tell me how somebody got rich on DogeCoin and maybe 1 will consider giving it further thought and their own research.   

 Last time I visited 10 years ago, paper money was more widely accepted than Visa/Mastercard; even in Berlin :)

Why I was curious of the development of this. Seems on social media posts that some hipp bars in Berlin now and then take crypto payments for drinks, at least xD 

 Yeah... Covid did help a little with the paper slips I guess, but as a precaution I'd still recommend visitors to prepare themself for a not so friendly german-stare when pulling out the credit card at a small coffee shop or bakery 😉