The vehicle manufacturer are the ones that decide how they want a particular vehicle to "ride". They do this with extensive testing, working with tire manufacturers, to get a tire that gives them what they are looking for. Based on this test, they usually choose two tire brands that provide the ride they are looking for. (Full discloser: I am a retired Michelin Employee)
I have a 97 Eddie Bauer Expedition and recently as of last year bought a 2019 LTX MAX. The 2019 came with Cooper tires and the ride was horrible as well as a harmonic shimmy that showed up as I reached 58 MPH. In due time (like soon) I replaced them with Michelin Defenders. With the Defenders the ride became glassy smooth and quiet. I have had a number of passengers comment on this.
The perceived ride is affected by:
1. The distance between the front and rear axles.
2. The suspension.
3. The diameter of the tire.
4. The height of the sidewall.
5. Air pressure
6. And finally, the Princess and the Pea effect. (Japanese auto test drivers are notorious for this.)
The longer the distance between the front and rear axles, the less the angular movement of the chassis as the front and rear of the vehicle independently rise and dip in the road.
The suspension on my 97 is adjusted to give a little more ground clearance. This is apparent when the two vehicles are parked side by side. The front suspension is adjusted by a long torque rod on each side that adds or reduces torque on the suspension arm which in turn rises or lowers the chassis. Increasing the clearance height generally add more stiffness to the ride. The 97 definitely has a stiffer ride. I would trust the four wheel 97 in bad off-road conditions more so than I would the 2019 Expedition even though they both are shod in Defenders.
The diameter of the tire. When you're looking for a good rolling toolbox, a larger diameter castor wheel is always better than a smaller diameter wheel. The smaller wheel snags on every little piece of debris on the floor as well hitting hard when rolling over joints between concrete pads. When rolling a toolbox with small wheels it vibrates and rattles like a 58 chevy truck, whereas a larger diameter wheel rolls much smoother over floor imperfections. Same thing with a vehicle and road imperfections.
Believe or not, most of the road vibrations are absorbed by the sidewall of a tire. The ability of the sidewall to absorb vibration is in the height of the side wall (In a 255/55 size tire, the height of the sidewall is 55% of 255mm or 140.25mm.) and the internal belt package of the sidewall. The belt package changes according to the load rating of the tire. The higher the load rating the stiffer (thus affecting the ride) the sidewalls when comparing two tires of the same size, but each have a different load rating. There is a market identified by tire companies which consist of "young men who spend inordinate amount of money on ordinary vehicles". Whenever I see a vehicle riding on rubber band (extreme low profile and expensive) tires on an older vehicle. I see a vehicle that is going to get the hell beat out of its suspension system, trying to absorb vibrations it was never designed to encounter.
The tire manufacturer sets an air pressure range in which it is safe to operate that model tire. They are only concerned about tire safety and life of tire, not ride comfort. It is the vehicle manufacturer the sets the operating tire pressure for a vehicle that achieves the type of ride marketing is looking for. That pressure is marked on the tag in the door frame and is always within the tire manufacturer pressure range marked on the tire. If you're inclined to search for better ride by changing tire pressure, stay within the pressures given on the sidewall and know that the lower the pressure the more heat is generated in the tire. And heat has an adverse effect on tire life.
Lastly, your butt, the ride comfort monitor. They are a lot like opinions, everyone has one and oft times have different sensitivities.