Social Democracies cannot get to Communism without revolution and replacement with Socialism. This is because the dominant system in Social Democracy, especially the nordic countries, is Capitalism and Imperialism. They fund their safety nets from massive exploitation of the Global South with brutal IMF loans, exporting Capital for outsourcing production, and more, they are parasitic.

Further, European Social Democracies are seeing sliding worker protections and social safety nets. Because the Capitalists are in control, they wear down the safety nets via austerity politics to further their profits. This is due to the Tendency for the Rate of Profit to Fall, Capitalists are forced to expand internationally and seek further and further exploitation due to competition forcing rates of profit down, so they counteract by expanding to raise absolute profits. Austerity measures are one example of Capitalists lowering their expenditures.

Next, Socialism is democratic. Whether it be the Soviet Model (for more in-depth accounting of it, Soviet Democracy by American Pat Sloan who participated in and observed it directly in the 1930s), or otherwise, Socialism has always been democratic. The Dictatorship of the Proletariat is the dictatorship by the proletarian class as a whole against the bourgeois clasd as a whole, as a direct contrast to liberal democratic dictatorships of the bourgeoisie found in the world over, including European Social Democracy.

Social Safety Nets alone are not Worker supremacy over Capital, hence why the US saw the erosion of social safety nets from FDR to complete obliteration, and why we are seeing the same trend in European countries. This is unavoidable as long as Capital is the dominant factor in the economy and humans are not, due to the Tendency for the Rate of Profit to Fall. In 1900, Rosa Luxemburg already proved why this is the case in Reform or Revolution. Reformism has never worked, because it cannot work. Even when a Communist does get in via existing democratic systems, such as Salvadore Allende in Chile, they get couped by the national bourgeoisie with the aid of Imperialist countries like the United States or EU.

Finally, there is no "true communism." Every country will have a different path to Communism, but certain factors will remain the same, such as the necessity of revolution. The idea of a pure, untainted "true communism" that has never been actually tried is a western-chauvanistic attitude that necessitates that workers in AES countries are simply "too dumb" to understand what communism is or how to build it, despite their real, practical work. The only Communism is the kind that exists in the real world, not in the figments of imagination alone.

You would do well to watch Dr. Michael Parenti's 1986 lecture and read his seminal historical book Blackshirts and Reds.