This is also my concern, that it does not look realistic and hence my initiative to start commenting in the topic. What is the reality and intention of only privately held companies with such small fares?

What i've heard is that, before, Renfe had a monopoly and since these new players came into picture, the prices have dropped dramatically in Renfe ticket fares. So definitely is good to see the benefits, but is it now also Renfe losing money and would the quality decrease? This would be a bad scenario for everyone then.