My regular LCC commute is with Eurowings from DUS to BHX. I average around 20 sectors per year with them alone. Since January 2017 to this day more than 60% of my flights have been delayed in excess of 30 minutes and anything up to 3hrs. It has become a major source of frustration. I'm of the opinion that it is quite simply because of their very tight planned turnaround times in order to maximise aircraft utilisation. There are no longer sufficient buffers incorporated in an aircraft's daily scheduled rotations to recover from any delays which may be picked up during the day.