I was curious to see if anyone thought the upswing could be promising!
The site's https://www.menucosm.com since you asked!
That said, I think the biggest issue right now may be the question of why this site is useful, given that so many other companies are doing the same thing. At a glance, it seems like it's competing with the likes of Yelp, TripAdvisor and Google Maps, all of which have significantly more data, large communities behind them and more features overall.
Unfortunately, the features it does lack here are generally some of the ones that these sites got popular for in the first place. Such as being able to create an account to upload pictures, rate restaurants and leave reviews, or (for a restaurant owner) to manage the listing and add extra information/respond to feedback.
By not having these, there's not really much of a reason to come back to the service time after time. It lacks the stickiness required for any real user retention.
I know for sure that I'd be unlikely to return after visiting, simply because the other options would have more to draw me in.
So yeah, focus on those features, get some more backlinks and try out a few paid ads and see what happens from there.
P.S. Don't worry, you're not the only person to struggle with this sort of site. It's a tough market to succeed in, and a company I previously worked for tried to do the same thing with much the same results.
In terms of functionality, yes, there's LOTS more I could build for sure, both from the regular user and the restaurant owner sides. I was trying to keep it quite minimal, but now that you point it out, it's obvious the site needs to be more engaging.