Spineless, unprincipled, constantly making excuses about why they're not doing anything, unwilling to do literally fucking ANYTHING to help the people they say they represent.
What are the underlying material conditions driving this?
Here in BC, Canada, the "social democratic" NDP government recently got a majority government, which means they can do literally anything they want. Pass any legislation they want. Pass any laws, any taxes, literally whatever the fuck they want.
And what have they done? FUCK ALL. Nothing. Not a single piece of legislation that I can think of. They're taking as long as they possibly can to implement $15 minimum wage, no paid sick days, no card check legislation, fucking NOTHING. Instead of using the pandemic as the obvious reason to pass this legislation they are hiding behind it as their excuse to avoid doing literally anything useful.
This seems to be the case all over the Western world.
WHY?
Since nobody has said it, I feel it is important to add that these parties still act at the behest of their country's imperial overlords in the USA. Almost the entire world's financial industry operates on the US dollar. It doesn't matter which party wins in the imperial periphery (including the 'western' states which are dominated by US finance capital) because the US has a vice on their economy and so they will act in the interests of US capital. Like all aspects of capitalism, it isn't really a conspiracy as much as it is self selected, and the vice is tighter on non-western countries. Only the organized working classes in any given country can threaten a social democratic party more than US finance capital can. Only then will a social democratic party actually do social democracy.