Some don't in Finland. But then it is back to basic rule of yielding to traffic from right. Which is pretty common on smaller roads so drivers should think about it enough.

> that does not seem a signaling problem.

Average signaling in Poland be like

https://files.catbox.moe/ipl96o.png

Are the words critical? As a German I read that as "you are not the priority road; you may only go left or right, but not straight"?

The words sum up to "don't go straight unless you have business being there" but still, it really sums up the approach to signaling. Nobody in the whole command chain sat and thought "that might be a tiny bit difficult to parse".

I mostly read those signs as “don't go there unless you already know you can” which as a “tourist” I just assume can't (unless I'm a local, and figure it out).

What I've recently found troubling is the places that use similar signs for emissions controls. With a rental you usually have a recent enough car that you can ignore those.

Being able to distinguish between “low emissions zone, but any car from this decade can go in” and “local traffic only, you need to live in this neighborhood to enter” in a foreign language, bit me a couple of times while traveling.

I get your point, but historical centre of Warsaw is as much not average as it can be.