It's been quite a long time since the first cryptocurrency with the "Mimblewimble" privacy technique was released. My first days of using GRIN were quite troublesome due to its added complexity. But it's a great coin to use for privacy-oriented transactions once you get the hang of it. Somehow, GRIN became a forgotten cryptocurrency as all of the attention shifted back to Monero. Was this a result of poor marketing/promotion efforts? Or a lack of user experience?
Heard about this for the first time from this post. Found it after looking into coinmarketcap. it indeed looks very good. I think it is very underrated . as you said maybe it is lack of marketing because I think it could've a bigger community if it was properly marketed. I'm wondering if this coin still has a future, especially when privacy on crypto has been frowned upon by mainstream governments. Do you think it can be good long-term investment like Monero? Or is it a complete bust? Your input would be greatly appreciated. Thank you very much. 
Right now nothing is certain about Privacy Coins. the big coins are in trouble getting delisted by big exchanges. so can't say how would this one do in such environment.. maybe if it was famous like monero and other privacy coins it would've been hit by govt too.I would not long this coin for now.