The definition of socialism isn’t so restrictive as to only mean “worker control of the means of production”. Social democrats, demsocs, anarchists, etc all emerge from a similar socialist tradition. Strengthening the welfare state is in the vein of the socialist ethos even if it doesn’t fundamentally change the relation of the worker to capital. Programs like Medicare for All and free public education are fairly described as socialist because they decommodify industries and shift them to public rather than private control.