how much of a difference on ride comfort can tires really make?

i have a pic related, 2017 w213 avantgarde with normal suspension (not airmatic) on 17 inch wheels fitted with 225/55 r17 continental ecocontact 6 tires and i feel like it doesnt ride as it should. i can feel every little imperfection on the road and when i go over speed bumps or potholes it takes a while to "settle down" as opposed to pretty much any other car i ever had which might take it harder, but at least it was fraction of a second and it was done. with this mercedes its like every bump in the road shakes the car for a full second or two. it is more comforable the faster i go and on very smooth roads it drives excellent

i just had yearly inspection and it passed with flying colors, so there isnt anything wrong with the suspension. so now im wondering if the car is simply shit or is it due to bad tires. they are one of those low rolling resistance models for better economy types so naturally they are harder, but if im not mistaken they arent runflat (which are even more hard). this same car could be specced with 19 inch wheels and runflat tires and here i am with 17 inch ones and i feel like it's undriveable. btw, its not like im used to "better" cars, my 2014 golf 7 gtd, 2010 e90 320d, 2013 skoda octavia all felt like they absorbed the road better