The struggle is not with the intent to successfully achieve post-scarcity communism, but to get as close as we possibly can, and once we get past efforts by the elite to sabotage those efforts, we can get pretty far (and have done so).
Think similarly to the objective to eliminate all petty crime in a society. You may never succeed, but you can reduce crime so that the rates are the lowest ever, and then go lower, and so on.
It's not all that hard. We already have (or had -- we're in regime change now) socialist programs that target low-income demographics (e.g. SNAP) and we have socialist programs that provide for everyone (e.g. CDC) and socialist programs that provide for general use (e.g. the NHTSA). We have libraries, the post office, the space program, and so on.
Communism happens by extending this communal infrastructure as far and wide as possible without privatizing it (the way George W. Bush did with Social Security pharma coverage), up to and including things like food and home production, mass transit and so on.
We've seen the Soviet Union fail to make communism work before corruption (and sabotage by the elites) overran their infrastructure. Similar we've seen the US fail to make democracy work before corruption (and sabotage by elites) overran the elections.
We try, try, again until we get over that damn hill.