Also, Marx's own view of consumption is that it's a real social need which capitalism itself restricts only to the bourgeoisie (we could also add the labour aristocracy) while the vast majority cannot engage in consumption like they need to. Of course, the goal here isn't a form of bourgeois luxury, but the ability of everyone to live a fulfilling life.

IMO communism will not prevail through celebrating austerity

Exactly, and there was quite a big debate around this in the early years after the October revolution and the founding of the USSR (as there seems to be every time a revolution manages to survive the initial time of great crisis and then needs to build up the forces of production and increase quality of life). After the horrors of WW1 and the civil war, both caused by capitalism, there was a long period of crisis which meant that no one really had a lot, and the little that people had, they had to all share equally. It was a sort of rationing program that was necessary during the wars. This, however, cannot be continued forever, and both Lenin and Stalin (and others) understood this. It's why the NEP was necessary, but these decisions caused outcry from some Soviet and even Wester European socialists who didn't understand the actual situation, but clung on to an abstract principle.

From Losurdo's 'Stalin: History and Critique of a Black Legend':

In the climate of horror at the carnage caused by capitalism and the auri sacra fames [accursed hunger for gold], a religious distrust of gold and of wealth as such is reproduced, alongside the idealization of poverty or at least of scarcity, understood and experienced as an expression of spiritual fullness or revolutionary rigor. And Stalin felt compelled to emphasize a central point: “It would be absurd to think that socialism can be built on the basis of poverty and privation, on the basis of reducing personal requirements and lowering the standard of living to the level of the poor”; instead, “socialism can be built only on the basis of a vigorous growth of the productive forces of society” and “on the basis of the prosperity of the working people,” for that matter, “a prosperous and cultured life for all members of society.”