When travelling in Australia, my Australian friends would insist that we do not tip in restaurants. Part of this is the real fear that American tipping culture would take hold locally. American's I know typically protest and don't feel they are doing any wrong and part of the tipping process is to make themselves feel good/generous even in places where it really isn't expected. When I have have interacted with locals in Italy, Germany and Spain, they really aren't tipping that much, just a little round up sometimes if you are eating outside of tourist areas that are not frequented by Americans. I usually spy the checks at tables of locals next to us and usually confirm there isn't much tipping (a Euro here and there). And in places like France, some nicer places will say on the bottom of the menu "Service compris" and no tip is expected.
I find it interesting that so many online "guides" are written by self serving people in the industry who may upcharge what tip is expected. That's why you are seeing American "guides" saying the correct tip at restaurants these days is 20-25% when the average is closer to 18% Tipping average USA Today. Another source at the Motley Fool says the average American tips 15%.
It's a little harder to ask local clients of European providers if they tip (except maybe in this forum) but I suspect that since tipping culture hasn't really penetrated in most aspects of life in European countries (eg hair dressers, delivery, taxis, hotels etc) that it isn't expected in providers either. Of course "it's appreciated", I would be too if someone gave me free money, but the other part of me feels that this is an import of an American custom that ultimately isn't a good thing. My Australian friends say they don't like the custom spreading as it might incentivize employers to pay less since their employees are now getting tipped. Plus we can see the dystopia of tipping culture in the US and want to stop it heading in that direction in our countries. I'm old enough to remember a time that tipping housekeeping in Canadian hotels was not a thing (still isn't in most of Asia). Especially since hotel staff in the big international chain hotels in Canada tend to be unionized with union contracts.