Try this:
1. Go post one of these mansion photos on Instagram right now without any hashtags:
Hashtags work.
Hashtags will relatively only bring you very little traffic, that is why they can be good if you have 1000 followers! They will bring in the botters that are liking and commenting by hashtags. If you have 2k+ likes, hashtags are relatively useless, at that point you shouldn't really care about an extra 50 likes or not. In your case, of course if I start a new account, I dont have any followers and as such I have to rely on the botters to like on my hashtags, and I might get 50 likes, as if I don't use hashtags and dont have any followers, of course I'll get 0!
Me @VapeMonkey @Jaymien are talking about hashtags in a little bigger perspective. I can have 4 digit figures differences in likes from day to day, if you look at bigger accounts you can see they can easily have 10ks of differences in likes and they are sometimes using some random hashtags. I can nail the top of any hashtag in my niche, it does not bring me in more likes. Why do I use hashtags then? Just as small tool to see how well my posts do, the better they do, the longer they can stay at the top of the bigger hashtags.