How much do you weigh and how much weight will you be packing?
You might not want to go fast, but I don't imagine that you want to have to make more pedaling effort than necessary. As your weight goes up, and your speed stays low, rolling resistance accounts for a large part of your effort on flat terrain. At higher speeds, aerodynamic drag accounts for most of the effort. Going up hills, lifting the weight accounts for most of the effort.
It used to be that "touring bikes" were nearly identical to road bikes. Look at classic touring bikes like the Dawes Galaxy or Miyata 1000 LT. Nowadays, "touring" bikes are 32 pounds beasts littered with braze-ons for bolting I don't know, 60 or 100 pounds of junk to them, and they roll on 2-inch tires. They're often lumped together with "all-road" "gravel" and "trail" bikes and even "commuters." Depending on how much you weigh and how much weight you're going to haul and the terrain you'll ride, these might be the best thing. For me, I don't want to tour on an all-terrain, four-wheel drive, heavy cargo freighting truck just to entertain the pretense of being on a transcontinental expedition.
It's not uncommon for people to dismiss excess weight on "touring" bikes because they will be loaded with enough luggage that a few grams in the groupset become insignificant. There is sense in that, but because it's possible to avoid as much as 12 or 15 pounds of excess bike weight, I don't think it should be dismissed, particularly if that's half the weight of the luggage being added.