Disclaimer - I'm not a Rally driver, never will be, and have never driven a car off road - well not more than about 10mph, so you can take what I say here with a pinch of salt I guess.
I tried out Dirt Rally, Dirt 4, and WRC 7 back to back this weekend on PS4 Pro with a G29, just on the introductory rally levels and my conclusions are:
Dirt Rally > WRC 7 >>> Dirt 4
With Dirt Rally I really felt I had a connection to the car. The wheel was giving me meaningful FFB, and it managed the "suspension of disbelief" of tricking me into thinking I was actually a Rally Driver. The car felt a bit light though through it's willingness to respond to every tiny input. However it was really fun.
WRC 7 didn't give me the same connection as Dirt Rally with the FFB being a little too "chattery" and at times seemingly more for effect than imparting any real information. That said the car drove well and intuitively, but not to the same level as Dirt Rally. Still fun though
Dirt 4 (on simulation setting) failed to connect me to the car whatsoever. OK, the car turned when I turned the wheel, but in much the same way a boat turns when you move the rudder. In fact that's a good way of saying it - it felt like I was driving a boat in comparison. Completing the first level was a bit grindy - I wasn't enjoying it, and it seemed more like hard work, lacking the fun elements of the other two.
Of course there's only so much a 30 minute sitting with each game can tell you, but I do know that if this was 20 years ago in a video game shop demoing all three to decide which one toi spend my hard earned on, then I would have walked away with Dirt Rally without question.