As others have said,
Tap-to-pay credit card very much the norm in Europe. Even in places you wouldn’t think take card have little portable card readers. For you, the traveller, having a card that doesn’t charge a foreign transaction fee and a bank that reimburses ATM fees is paramount. Those fees DO add up (I once had about $50 in money wasted on those fees during a 3 week vacation to Europe). Having the Chase Sapphire Reserve solved that problem while also giving me Priority Pass access (but, yes, the recent annual fee hike is eye watering).
When paying by card, sometimes we’re given the option of selecting a currency to pay in. Always choose the option that is NOT US Dollars.
While a theme of this thread is avoiding money waste, it behooves us to be familiar with the tipping culture of the country we are in. The 20-30% that we’re accustomed to here is insane just about anywhere else. General rule is 10%. If I visit a new country and get pushback and/or strange looks when attempting to tip the generic 10%, I usually cease and desist from trying from that point on while in that country. On that note, even though it’s Asia and not Europe, in Japan you never tip anyone, ever, under any circumstances. Some countries in Europe are not far off, but 10% is a good ‘general’ rule of thumb when you’re not acquainted with the norm of the land. I have some friends that can’t seem to grasp this because they feel ‘bad’ not tipping generously. It’s really best to ‘read the room’ so you’re not wasting money and making yourself look like some arrogant show-off in the process.
And, yes, while cash is becoming less and less necessary in much of Europe, there are still instances when it’s the only form of payment accepted. Oktoberfest (and other similar Volksfests) in Germany is a prime example.
PHD-level move on my part — a few years ago the USD was briefly worth more than the Euro. During that period I was raiding every ATM I could
find and withdrawing the max allowable cash amount while the dollar was so strong. Withdrew almost $2,000 worth. Wish I had taken more (I go to Oktoberfest every year lol). 😁