Endurance and gravel bikes tend to be designed with shorter reach and more stack (less drop) than full on road racing bikes. I'm 75 inches tall and based on a recent fit, my current bike's reach of 396 mm requires 150 mm stem. I would prefer an endurance frame but all the ones of interest have short reaches. Few bikes have say 410 mm reach. Anyway, I would say gravel and endurance frames inherently put a rider in a more upright position with less reach and less drop.

A more upright position puts the torso in a less cantilevered angle, which puts less demand on the stabilizing muscles of the trunk or core and also a lot less stress on neck muscles and less pressure overall on the upper neck/shoulders. That is just physics. A lot of riders aren't positioned optimally on the bike. Often the saddle is too high with chafed butt resulting and/or knee issues.

When I was young and flexible and strong, it was easy to ride with a long reach and drop because making more power on the pedals meant the legs support a lot of the weight and being skinnier meant less weight to support. A stronger core also made it relatively easier to ride with a flat back and horizontal forearms. Saddle fore and aft come into play as well. As the saddle is pushed more forward or as seat tube angles increase, more weight is shifted to the hands. A cm one way of the other can make a big difference. It is somewhat rare to see an older rider with a flat back and horizontal forearms. It is also hard to tell the age of a rider just seeing them on the road. Is someone 60 or 40? There is a world of difference between the two ages statistically WRT riding position

Bike fits are very expensive and may or may not be worth exploring.......