Regarding that video of the MD82 take off, as commented on, there wasn’t much runway left, although the plane seemed slow to build up speed.
I looked at the runway length needed for the MD82, thinking that maybe it would need a longer runway due to aircraft age, plus they substituted the aircraft on the next trip.
Cardiff Airport runway length 2392m/7847 ft
MD82 take off distance 2225m/7300ft variable
A320 take of distance 2250m/7400ft variable (inc distance to reject take off).
I realise there are are many variables such as passenger load, full fuel, wet/dry runway, height of runway above sea level, engine type, etc.