I thru-hiked the Cohos Trail in 2017, north to south. That was long before COVID made hiking the thing it is now. The trail was virtually non-existent in sections, and blazes were few and far between, and inadequate. It was really challenging, I have to admit. After the first night, my buddy lagged behind and I was alone, and I used the map, the guidebook, and my compass constantly. (Now, of course, people just whip out their phones).
To get to the point, the good people at the CTA have built a lean-to or two more since then, the trail, I am told, is now nicely blazed, and there are some much-needed bog bridges in place.
I was grateful for the B&B halfway through, operated by the woman (who, at least at the time), was the CTA treasurer. I left a box with food supplies there before we drove up. I did laundry, re-packed, she cooked a wonderful dinner. There was WIFI, and appreciated re-entering humanity for a night.
But with that, I never felt the need for more facilities than we had. I stayed at a motel just off Waumbek. Those two nights (out of my eight) were the only times I was camping in a tent or at a shelter.
It's remote out there! But that's part of the problem, I just don't think there is a demand for another facility. I think for most people, they go to the mountains to check off their 52 With a View lists or whatever, and then they head back down.
But it is good to ask!