I'm surprised people are saying they felt it was too empty. Too me it felt too cramped. Played the first half of the time on Nov 1 just regular follow the quests style but once I hit about level 7-8 I went out exploring most of the southwestern quarter of the map looking for a place too build and there were so many no build places which was frustrating. Also The blueprint system is pretty janky, and I had built in one area then logged for 20 minutes and came back with other people building on my spot so my camp didnt spawn...which kind of shows me moving your camp quite a few times is intentional and expected considering the value of real estate.
As to the no NPC nonsense, there was a Super Mutant trader wandering the roads, think his name was Gareth and his Brahmin Moo-Moo. There's also robots in abundance. I also imagine once they start doing expansion packs new areas will have survivors, you can tell that what they were going for was this whole "There were clearly survivors up until just recently, so what happened to them?" story.
Not sure if I like or hate the card perk system yet tbh. Not much in the way of player agency and it looks like skills like Lockpicking are tied to them saddly, but it's understandable from a balance standpoint.
I played solo which was perfectly doable, since it seems it shares a tagging system similar to modern MMO's where just as long as you hit something it'll have loot. Containers out in the world also seemed like the loot inside was spawned individually since there were always things in a few of them even when an area had a bunch of players. The Crafting system is much improved on from the Fallout 4 system, as you can actually create weapons and armor instead of just modding them...which you can also still do. Also learn to spot fallen logs, wood is probably your most valuable building resource. I am hoping that the building radius on your camp can be extended in the future because building is definitely the selling point to any type of survival game and right now it's literally just enough to throw up a shack.
So yeah, my biggest gripes are that I wish the map was actually bigger and more empty, and that your build radius is so limited if you do find a place you actually wish to build. I think too many people are judging it based on it's namesake than they are on it's entry into the survival genre, which I honestly feel makes some big leaps forwards but also some steps back. Can't chop down trees or break rocks, but there's TONS more to do than "build cube, wait till anti-socials destroy your shit, wait till they're offline to do the same". It REALLY needs a text chatbox though, fuck the always online mics, hearing people describing their character creation while I was creating my own character was aggravating.