I'm also Scandinavian (Norwegian), and I never tip when going out.

I can't think of any long-term outcome of a tipping culture that is efficient for the workers and employers, even if the amount the customer tipped was correlated with quality (the research I've read shows it's got more to do with looks). It is simply more efficient that both parties know what they are agreeing to up front when (1) the worker still has to go to work for 3 months when they resign and (2) the employer has to pay them (and their replacement) full wages during training.

I tip (live in US) as we are shamed into it, but I find the relationship between the customer and staff subservient and dehumanizing. The service folks must do the dance and check on you every 5 minutes ("Are we doing good here, hon?) while I in turn must come up with a fake smile and a thumbs up. What else am I gonna do? It's all kinds of weird but unlikely to change.

A couple of decades ago I had a waiter run out to the street after me, midtown Manhattan, a sushi/tappas place, sternly inquiring as to why I didn't tip them. I simply forgot, it was very late. I didn't need that.

It's definitely efficient for the worker. There's no employee tax or income tax on that money. The worker just gets the money directly.

I never tip because if burger with fries costs €15 then we had a fucking legal contract that you'll give me a burger with fries for €15, don't be like "uuuuuuh sir I'm going to ruin your evening by asking you to pay more at the checkout time because reasons".