The big thing with Photogrammetry are the details. You can sculpt and model high poly, but you can’t ever get perfect recreations of details, since the level of detail in the real world goes down farther than subatomic particles. So, with photogrammetry, you are measuring that detail with light, and recreating it. Now, you can use a low poly object and place those details on them, and will get more realistic looking detail than spending 10 times as much time detailing it in Zbrush.
But Photogrammetry is more expensive than Zbrush, if you want the best quality, and is a memory limited operation on a computer, meaning a computer with 128GB or memory will doe the job faster than a computer that is twice as fast with half the ram. Multiple GPUs help, as long as the program you use uses them. Agisoft is great because of this.
You don’t have to go to exotic locations, since the thing you want is detail, and colors are secondary to this. So if you want foilage, take an interest in some scientific plant classifications, find cousins of the plant you actually want the details for, and then manipulate the colors at the end to look like the desired plant. Bricks are the same around the world, and rocks can be found at your local swimming hole. Bark on trees are varied, but you can find endless assortments all around the world.
All of this takes time to shoot tons of pictures, and then the computer processing time. In the end, they had a team of more than 20 people over 3 months times, which is something like 2160 man hours, not including all the tasks they let run overnight to do the actual photogrammetry. Building a library of these types of assets that can be reused will be worth the time, if you have the time/money to spend to do it.