I know that some American tourists actually do this, on giving servers cash tips as if they’re underpaid by their employer (since they’re used to it in the USA along with growing up with that mindset) but overlook the fact that servers are paid the minimum wage in the EU, as it’s not “typically” the norm. This practice is being exported it seems, in another region where that isn’t common.
Not unless Europe is somehow also under the illusion that they should reduce restaurant wages to a fraction of the legal minimum.
Tipping in the US is to make up for their atrocious low wages. EU workers don’t face the same wage stagnation.