So, the subscription benefits are pretty limited. I haven't subscribed.

• You can play in a private world, but I haven't found a lot of reason to do that. You generally benefit somewhat from having other players for multiplayer events, and outside of that, they're pretty much a non-factor. IIRC you can tweak some world parameters for those, can't recall what.

• You can slightly accelerate getting some in-game items that you can get anyway.

• You can get a "scrap box" that can hold an unlimited amount of scrap. Some people apparently get this for one month, stuff it with huge amounts of scrap in a month, and then cancel their subscription. They keep the scrapbox, can take stuff out just can't add more to it. There isn't all that much you can do with scrap. Maybe if you're super-into building pretty CAMPs.

• You get a small inflow of "atoms" to use in the store for in-app purchase via playing. A subscription will give you more. Most of the stuff you buy is not all that amazing (to me, at least):

• You can buy some mostly-cosmetic items to decorate your CAMP. Some people...really get into playing SimArchitect or something with their CAMP. Like the Fallout 4 settlement building in a smaller radius, but you can do it almost anywhere and people can show off their CAMP. I don't care about that (though I have seen a handful of other people's CAMPs that are amazing. I remember one that looked like a big ship in the Mire.)

• You can get more SHELTER maps. These are kind of a private building area that you can reach from a hatch in your CAMP on the main world. I don't care about this. The differences between these are basically cosmetic. Some are bigger, but you really aren't space-constrained. I think that they were originally intended to play into a survival aspect, where you had to hide from radstorms underground or something, but most of the game's survival aspects were nerfed after players didn't like them. Radstorms are very weak and very rare.

• You can get alternate weapon skins. This is actually useful, because if you have multiple weapons of a type with different weapon mods, it's nice to be able to distinguish between them.

• You can get some alternate, cosmetic, outfits. Given that I usually have a first person camera and don't play with anyone I know, this does little.

The main reason I would be interested in a single-player environment would be Fallout 4-style modding, which isn't really an option in Fallout 76, even with a private world, or if players were a pain, which I really haven't found them to be (and I'm pretty unenthusiastic about nearly all multiplayer games. I play Wargame in single-player mode. I honestly don't think that a private world is likely to buy most people much.)

From my standpoint, the initial, up-front purchase price gets pretty much everything interesting.

EDIT: Oh, and if your concern is gathering plants and stuff like that, IIRC that's per-player anyway. If someone's gathered plants and they haven't regrown, I don't think that they look gathered to you.