I’m quite curious if this was due to leftwing parties changing the way they talk and going back to politics anchored on principles or if it was something else.

In my own country (Portugal) mainstream supposedly-left are soft neolibs, then there are the Communists (sadly mere slogan parroters invariably putting Party above Principle and hence amongst other things supporters of Putin) and the “thinking” Left who are quite out of touch middle class scions of the middle class (well intended-ish but societally ignorant people who were born with a silver spoon on their mouths and live in a very local - in a country were half the population is emigrated, almost none have actually lived abroad - bubble of relative priviledge) whose style of presentation is the same as the politicians from the “supposedly-left mainstream party” and who have copied the liberal take on Equality (from America, a country that pretty much only has hard-right and far-right, so it’s hardly a leftwing “equality for all” take) rather than the principled, identity-agnostic take on Equality. Also they obcess about the far-right, in practice helping them grow (it’s a well known phenomenon in Propanda that if a Party is constantly talked about by others, even if only to criticise them, they get perceived as important and end up growing). Unsurprisingly the entire mainstream is losing votes just like everywhere else, the alternative Left has recently collapsed to half the size it one was and only the far right is growing (which in my country is one ultra-neolib party and a fascist one).

It would be great if the Left in Finland had found a solution for this that’s culturally-agnostic and hence applies all over Europe directly, rather than be dependent on the kind of cultural factors that take the 4 decades or so these things usually take to get to Portugal from Northern Europe.