Heeling is when the sailboat leans over to one side due to wind pressure on the sails.
Monohull heeling. This is because they offer a level of comfort which for some makes the difference between setting off on that life-long dream of a trip and staying at home. A monohull simply cant be compared to a cat in this regard. Their wide stance provides little to no heeling.
Stability is a big plus for families with young children or seniors who are not particularly steady on their feet. Much less heeling enclosed cockpit galley up with direct stand-up access speed for size of hull all seem appealing in the cat. To propel the boat the boat is angled so the wind crosses over the boat at an angle hitting the sails and pushing them toward one side of the boat.
Even when powered up a cat or tri will rarely heel more than 5-10 degrees before its time to reef. The centroid of the boats underwater volume is called B the centre of buoyancy. This ensures that when a monohull heels over once the pressure is removed from the sails the boat rights itself using gravity.
Multihulls can develop an unpleasant motion in a big sea Upwind most cruising multihulls wont point like a monohull with a deeper keel and when it gets lumpy and fresh the motion can become distinctly unpleasant. Monohulls like this Amel 55 sail better upwind and her ballast keel adds displacement which means comfort when its rough. Monohulls use heavy weighted keels suspended under water to keep the boat upright.
Motion was not terrible but sharp heels of more than 20 and sometimes 30 degrees definitely meant timing your steps and staying on the high. In theory no matter how much you heel gravity will not let the keel come out of the water in theory. The force of buoyancy is directed straight up through this point.
Sailing CATAMARAN in the ROUGH SEAAre apples better than oranges. A monohull has just the one hull and displaces its volume in water. Monohulls offer heeling faster steering response less noise from water slapping are cheaper to buy and maintain and have one hull.