I use it. I have THREE freakin accounts hahahah. I'm normally signed into my fitness account and that's my most active. I post about 7-10 times a week on there. Only 1 out of every 10 or more posts is actual product.
I know this sounds like the opposite of what most people say, but I find hashtags are mostly empty. If you tag stuff #etsy the only people who will probably find you are other sellers... not buyers. I usually use a few on my posts (I used to use dozens).. they get you a ton of likes, but not much interaction.
Common hashtags even lead to the problem of people using web programs to AUTO comment on those tags. You see accounts with 50k followers and they only follow 10 people? It's because they set up auto commenting. So, for example if I put #fitfam on a post, I will get a few comments like "fantastic!" "great!" or #recipe gets "looks delicious!" or "yumm!"... those people haven't even looked at your stuff and did not type that comment. They do auto comments in order to make you think they do, so you go follow/check them out. A computer program does it for them.
Honestly, interaction is the best way I've gotten followers. You can add as many hashtags as you want and you may get a few followers but if you don't follow them back instantly, they leave pretty quick. I search for hashtags and leave real comments on things, like a few photos, then move on. Or find an account similar to me that I enjoy, and see whos commenting on it and interact with them. It gets more return interaction than empty likes. I've never told someone who likes a necklace to go buy it. I reply and hold an actual conversation, or go to their page and interact there.
It's time consuming... but worth it. I'm coming up on close to 1000 followers now (which, yes I know isn't many), and have had a few sales. Plus, people who have purchased from me find me on instagram after and tag me in photos of their jewelry, which is even better! I use a repost app to repost their photo, with their name attached and they love getting the attention if they're a tiny account.