I have not been in a place in Europe where the tips would be rejected. However, universally they are not the norm or expected.

Also about the $10 - they would need to gather quite a few more dollar notes and spend time finding a cash exchange bureau. Else the note is just a memento of a weird American.

In some EU countries the tips have to be counted as salary and income (+social) tax paid, or even they have to be declared as revenue to the restaurant along with the VAT (19-25%) going straight to the state. Of course, when paid in cash - that rarely happens. The point is that the provision exists in the law (so the tips are not unheard of)

Define "the norm", because it's absolutely a thing, just not required and or demanded like it is in the USA.