It might be counter intuitive but using general purpose directories like ProductHunt or similar to showcase your project is likely just showing off to off-target, extreme churn, user base with high potential to becoming competitors.
In my opinion, the best and only place you should showcase your product is where your actual target customers are!
The best site in my opinion is Product Hunt. I look for new start ups here everyday. Also if you want to innovate a good strategy (if you already have a monetizable product) is to do an affiliate campaign where you should:
-Define buyer persona
-Find the affiliate leads
-Analyze which keywords are the more high intend
-Extract the leads of this blogs/web pages
-Launch an email campaign via GMASS
-Create the landing pages where you want the affiliates to redirect their traffic
If you are interested in this channel or any new growth channel, respond to it and I would gladly help you
Aren't you missing LinkedIn on your list? We get way more views on LinkedIn than on relevant Reddit communities for instance (we are a robotics SaaS startup).
In my opinion, the best and only place you should showcase your product is where your actual target customers are!