Of course reinforcing the labor movement is more important, strong unions are more important, revolutionary action is more important, but how can you claim that ameliorating the living conditions of the working class through socdemery isn't important?

It's not that seeking to improve the living conditions of the working class isn't important, it's that socdemery is a poor way to even do that. Campaigning for socdem parties and orienting social movements around political parties is an action that alienates working class self-organization to the bodies of the State, and even when this has the goal of establishing welfare-state policies that in principle can alleviate poverty and stabilize business cycles, is a tactic that backfires because it dis-empowers the proletariat (alienating decision-making and acting power to the State, instead of wielding it itself) as well as de-radicalizing the "socialists" who are joining the bourgeois theater.

The State is an institution with an inner logic of it's own and with permanent entrenched interests at all levels of it's bureaucracy, no party can simply participate in it with out being sucked into this inner logic or try to swim against the tide of the bureaucracy. I mean, observing the US presidential race as a South-American has been really funny because it seems no one on any side of the debate even knows how government works: Universal healthcare would obviously be a great change, but do Bernie supporters honestly believe he would have the political will-power to give free college and universal healthcare to the proletariat, as if the entrenched interests of the State bureaucracy and the current conditions of capitalism in crisis did not matter? A Bernie presidency would be indistinguishable from a Clinton presidency in all except maybe some details about foreign policy. Even a Trump presidency, unless he obtained dictatorial powers, wouldn't be too different from an 'average' Republican presidency - what is most scary about the Trump phenomenon is not the man himself but his supporters and the reactionary social forces they can directly unleash.

Moreover, government policy has to engage with how capitalism actually works. A State can't summon full employment when capitalism is undergoing a crisis of lacking profitability because doing so would deepen the recession even more. Look at how Social-Democracy in Venezuela tried to engage with the crisis through nationalization and price controls, and the ensuing capital flight just led to massive shortages and crumbling infrastructure. The living standards of the working class ultimately fell.

I'm a Brazilian and have seen this game being played before: PT (Worker's Party) rose to power with massive support from social movements, yet in order to play the parliamentary game and not disrupt the State bureaucracy or the capitalist economy too much all they could do was pursue small welfare-policies that are traditionally associated with liberalism (such as the Bolsa Família system of cash transfers). These policies while small did have a very positive impact in lowering poverty when combined with the Brazilian economic boom of the 2000's, however very quickly PT gave in to opportunism: Allying with socially reactionary religious fundamentalists, paralyzing all land reform efforts and allying with the latifundia, kicking thousands of poor people out of their homes to build the pathetic spectacle of the World Cup, making poor people massively indebted to rich construction companies under the guise of pursuing a serious urban reform, re-inforcing the police force and the army and their capacity to kick the autonomous social movements out of the streets; and meanwhile the once-vibrant social movements that led PT to power had become opportunistic shells of themselves, cheering for every one of these right-wing policies (because, after all, PT had lowered poverty so much!).

And after 14 years what did all of this amount to? The traditional right-wing strengthened itself at every step, the traditional left-wing social movements were completely defanged and turned into hotbeds of pathetic opportunism, the autonomous left social movements were kicked out of the street by the joint action of the PT and the traditional right-wing and Brazil is in a massive recession; and ultimately PT ended ousted from power by the traditional right-wing. Now they are reversing all of the small-but-positive changes that PT did while pursuing a terrifyingly reactionary program, as if the recession and stagflation had not already undone much of the positive change that happened between 2002 and 2013. The working class has largely stayed apathetic at the whole process because they don't have the willpower to defend PT at all, even though we all know that the coming Temer government is going to fuck shit up all that is left for us to do at this point is brace for impact and hope we won't fail to pay our rent.

How should the working class fight for better living conditions, if not through socdemery? Direct Action. Breaking with old union bureaucracies and engaging in serious strikes, forming their own mutual-aid networks independent of the State, forming local crime-watch and cop-watch councils and associations to protect themselves from systemic violence, occupying and taking abandoned state and private property and putting it to their own social ends, actively disrupting the functioning of capitalism and government. This sort of action would empower the proletariat to set the terms of how they want to improve their living conditions while compelling the government to seek reforms in order to make society governable again.