Gas plants have their main cost in running them. So if they only fill the gaps, their cost is reduced too. But yes, they are not to be considered "profitable" b

Gas plants have their main cost in running them. So if they only fill the gaps, their cost is reduced too. But yes, they are not to be considered "profitable" but rather as part of the infrastructure like powerlines. But as solar and wind costs only a fraction of gas when running, this is a good trade off.