Most “center” “left” parties in Europe nowadays are just Neoliberals (pro-business, pro-privatisation, pumping up asset bubbles and generally bough and paid for by moneyed interest) and hence not really Left and often not even Center.
However all countries in Europe still have real Left parties (even the UK with it’s highly rigged First Past The Post voting system has the Green Party), though judging by the one in my own country (of which I am a member) there’s often this messy mix of people whose leftwing thinking is basically slogans from the Soviet Union (these being mainly people in their 60s and older) and people who grew up in the post ideology neoliberal age for whom leftwing is basically greed but for-the-group instead of the individual (hence you end up with Identity Politics which is a twisted subverted charicature of the Fight For Equality that far too often is dominated by people who are members of a group they were born into demanding shit for their group - instead of a broad push for Equality done on the basis if need an independent of the “group” people were born into, we have competing pulls for getting shit per group, with people said to be deserving or undeserving based on the genetics they were born with, thus far too often rewarding some people who are priviledged but have the “right genetics” whilst not helping those who have real need and yet were born with the “wrong genetics”).
I don’t really know if the present day Left can find a modern ideology and vision that’s not just a “branch of neoliberalism that doesn’t talk of Economics”, though the victory of the NFP in France, lead by Melenchon and his party rather than the old “moderate” mainstream party - called Socialist but not in any way form or shape so, but rather just neolibs plus performatice leftwing talk - gives me hope.
From my experience living in a country with Proportional Vote, one with First Past The Post and one with something in between (multiple representatives per electoral circle) my conclusion is that Democracy works best with variety and frequent change - you don’t want Stability, because that just entrenches some people in control of the State and inevitably leads to frequent abuse of that power for personal upside maximisation, including via outright corruption, as well as the steady takeover of the various mechanisms of the State (most notably the subversion of the supposedly independent Pillar Of Democracy which is the Judicial System, something you see reaching its natural outcome right now in the US).
Change and many eyes with many conflicting interests and a real likelihood of reaching power are the best way to delay and even undo the natural subversion of the State by the kind of people who seek power - which happens in all systems, not just autocratic ones - whilst the highly stable “Two Party Systems” in supposed Democracies are barely better than dictatorships in their resilience to the rotting of the State from the inside.
Proportional Vote, which isn’t at all Mathematically rigged for “stability” is the best system I’ve seen so far at keeping the politicians in power from pillaging and subverting the State, mostly because they fear both their coalition partners (Government there is always by coalition) finding it out and using it for political advantage (by loudly bringing down government and triggering new elections in order to capture more votes) and that the next government might very well be a wholly different coalition whose politicians are not “people like them” and would just love to catch and bring to Justice any funny business done by the previous guys.
In places with two dominant parties that alternate in power, the politicians of both those parties make lots of noise for the audience simulating deep differences but often are mates and frequent the same social circles and even when they’re not there’s generally on subjects like Corruption a “gentleman’s agreement” of “I don’t go after you in my turn and you don’t go after me in your turn”.
Not even PV systems are immune to crooked politicians but they certainly seem way more resilient to their actions and even much more capable of self-healing before the rot is too far along.