It's really not common in much of Europe at least for people to actually discourage tipping (though they may seek to refuse what they perceive as exorbitant tips).
Tipping is mostly expected when there is a lot of service involved in the meal. This means either fine-dining, or Meyhanes where you spend 3-5 hours drinking heavily (Raki/Ouzo) and eating mezes & fish.
I think the tipping culture you're talking about is "Bakshish" which is really more of a bribe than a tip. It doesn't exist much in Turkiye anymore (unless you're an Arab or Syrian refugee, their experience is far different than others). Bakshish is still very prevalent throughout the lower Balkans, Serbia and most Islamic nations I've visited and worked in, except for KSA and UAE (they'll kill you for that shit.)
Definitely more of a bribe, and common in a lot of the world, in the countries mentioned but plenty of others, esp. the African ones I worked in; different names but same idea.
A "cost of doing business, and we appreciate the opportunity" gesture. Prove that you're serious, and that you want an actual result.
An Egyptian friend, once warned his friends about me: "Now he's American. When he says 2pm he means 2pm, and when he says we have to leave at 8, that means we have to leave at 8. This is why Americans are rich. They respect schedules, and care more abut business than friends or family."
Tip jars are perhaps a more recent phenomenon, but they are now almost ubiquitous in all places that serve anything, event at a counter or to go - including club bars, coffee shops, even many fast food places.
That's the key point.
Like just the other month I was in this resort with my family and first night we checked in we went for diner - waiter was very polite, entertained my one year old and gave us tips about the area. We didn't have cash on us so we put it on the room and signed the receipt. Next day he was still professional but not as much effort - then I left a tip for both dinners and suddenly it's back to chat mode, how was your stay, parting drink on the house, please do come back, etc.
In coffee shops you can see the looks you get when you wait for small change.
As a personal anecdote - when I visited America on a business trip we went to a restaurant where the staff was literally rude to us, the food order was not what we ordered and massively late, and yet our hosts insisted on leaving a 10% tip because
1) low tip will show them they have done a poor job(?!?!?!?!?!)
2) we would look like jerks for not tipping(their explanation).
So basically my takeaway is - if you have to tip even when your experience is poor, or you risk "looking like a jerk", then it's not really optional.
the irony!