I always find it strange when the Merit Order is criticized (rightly) with the argument that it is not a free market (wrong). The Merit Order principle simulates the free market in the case of excess demand. You just have to imagine it with apples. A farmer can produce 10 apples a day on his plantation at a price of 1 EUR (gross retail price) each. In the village, every person wants to eat one apple a day and there are only 10 inhabitants. It works out. Now the pear farmer comes along and also grows apples but can only produce apples on his pear-optimized plantations at 2 EUR each. As long as the demand is only 10 apples, he naturally won’t sell them (unless they taste better, but let's leave that aside). But once a year there is the apple cider festival and during the 10 days people need 2 apples per day, one to eat and one to drink. What happens then? Does the apple farmer sell his apples for 1 EUR and the pear farmer his for 2 EUR? No. Both can achieve a higher price until the demand is met. The pear farmer earns more than he otherwise would, since he now sells apples in addition. The apple farmer also earns more, since he makes more per apple.
Electricity is not a storable commodity and only poorly storable, but above all you don’t want supply to exceed demand (grid stability), so actually no one should produce more than they can sell. But if the demand (electricity demand) is higher than the supply of the "cheap providers," this should also be produced and at the same time the cheap providers should benefit from being able to produce more cheaply, as in a free market. That’s why the Merit Order principle exists.
I’m not saying that this is good and right, but Merit Order initially has not so much to do with market distortion, but with market simulation.