I find it interesting how your (US) experiences compare to mine.
In Poland, lane splitting is legal. Well, it's not explicitly forbidden, thus technically legal
, but it's accepted by the Police.
We get traffic jams on highways relatively rarely. Partially because we don't have many highways
People don't tend to work as far away from home and commute long distances, rush hours with all lanes of a highway barely crawl don't happen regularly. Of course, jams do form if there's an accident, but then it's usually full stop and you're not lane splitting as much as driving around stationary cars.
So lane splitting is mostly an inner city thing. Rush hours in our cities with those narrow old streets can be brutal and I can't imagine NOT filtering.
The first weeks of Spring are usually the dangerous ones, drivers need some time to come to terms that motorcycles are back on the road and start paying attention again. After that, I find it's relatively problem free. Usually either the traffic is crawling, so filtering is safer, or it's flowing and there's no need to filter in the first place.
I have a hypothesis that our drivers don't spend so much time in their phones because Euro cars tend to have manual transmissions more often. Harder to hold your phone if you need that hand for shifting.
I also have an unrelated hypothesis, that the riders that have lots of close calls and often complain about "cagers" are usually the ones that ride aggressively or are ego-driven. Some people just seem to enjoy feeling like the road is a battlefield and they're the action hero. Or maybe they can't ride defensively? I don't know, but I honestly can't relate with the "assume everyone's out to kill you" mentality, I get like maybe one close call per season? And maybe one or two drivers that I judge as actually spiteful or malicious, as opposed to inattentive? And I ride daily through the fourth-largest city in the country.