I have asked the same question, and I can provide you with the official ESA answer. Since 2018 ESA's studies have noticed an increase in demand for small, low LEO and LEO satellites coming from the private sector (mainly, but not only). The ELC, in the general the subsidizing of small, light-weight, reusable launchers aims to support this section of the market. So the official answer is that the ELC bets on the fact that yes, there will be enough demand to support some of these new independent launcher companies.
I have asked the same question, and I can provide you with the official ESA answer. Since 2018 ESA's studies have noticed an increase in demand for small, low LEO and LEO satellites coming from the private sector (mainly, but not only). The ELC, in the general the subsidizing of small, light-weight, reusable launchers aims to support this section of the market. So the official answer is that the ELC bets on the fact that yes, there will be enough demand to support some of these new independent launcher companies.