I think there are so many factors going into comfort that carbon vs steel is a hard argument for me to make.
I have a steel rando bike with wide tires. It is slower than my carbon rando bike, for sure. The steel bike has a suspension stem, a seatpost with a lot of give, a B17, and RH tires that measure 40mm. It has rim brakes. Overall, comfort is good.
The carbon bike has less drop to the bars and does not have a suspension stem or carbon bars. It has a seat post with a lot of give but a racing saddle. It has clipon bars. Aero wheels. I run GP5000 tubeless in the 30-34mm actual width range. I am about an hour per 200km faster on the aero carbon bike. In my case, the aero carbon bike is more comfortable to my neck but less so to the hands. Being faster means the fast kids drop me slower. Overall, comfort is a little better. Saddle is an issue and a works in progress. I might retrofit a suspension stem, carbon bars, and a different saddle. In which case, it would be no contest.
Fenders are a challenge with carbon. Cervelo, Trek and Cannondale make endurance frames that let you use fenders...Caledonia and Synapse and Domane. Delivery was over a year for the Trek and Cannondale in my size. I don't know if supply chain issues will impact your choice but something to consider early.