Especially in more open country, using your binos is easier for hill sides and basins, bitterbrush etc areas to glass into thats immediate to you. Seeing what you believe might be movements, or following what your hunting with the optic will be better served with the spotting scope, especially if you are trying to put it to bed. I usually break out the spotter after doing a quick snaked eye look of my immediate area and a few good grid scans into the areas in question once a glassing position
Much depends on where, and then how you prefer to hunt.
PA has for many decades been one of the top 4 states as for hunting license sales. Many of those hunters are long range only hunters, and some have been for a very long time.
The terrain in the NC region of the state is ideal for that type hunting due to steep mountains fairly close together, as well as some also having deep wide hollows to both glass and shoot across. However, it does not lend itself well to spot and stalk type hunting. Therefore virtually all long range hunting is done from a fixed location.
Locations are chosen, largely according to conditions such as sun angle, and changes in location are made for that reason as well.
In other words good in the am, poor in the pm,
or vice versa, unless of coarse it's an overcast day.
All the hunters will be using tripod mounted binnoculars, it would be extremely rare to see a spotting scope being used in conjunction with hand held binnoculars.
Some of the locations will be considerable distances to hike, and others will be very close to the vehicle. Regardless, the method of glassing wont vary.
If you were to spend an entire day driving from location to location, and saw 50 or more hunters in small groups, probably all 50 will be using 2 spotting scopes in machined adjustable brackets.
Some will be larger or smaller than others,
due to personal choice and of coarse cost, but all will be using them. Twin 80 mm Swarovskis or Kowas are now very common, as well as the now very old Bushnell scopes in both 50 and 60 mm which are by far the most popular. This is not a new thing, ive been using them for 45 years, and they have been around much longer than that.
Bausch & Lomb marketed them as a cataloug item in the 60s with their still excellent Balscope spotters.
As good as some of the modern day optics are, nothing can compare with twin spotters for extended long range glassing for various reasons.
Main ones being, power can easily be changed to match the situation by changing the eyepiece.
If they get knocked over and out of alignment, they can be fixed right on the spot easily unless glass has been broken.
No I don't sell them lol, but I might be helpful.