I ask because I personally became disillusioned with Duolingo's streaks and leaderboards. I found that I was forcing myself to use it every day but I lost the love of learning the language. Ultimately, I stopped using it because I had a lot of extrinsic motivation to hit targets in the app but little intrinsic motivation to keep learning.
It sounds like your experiences were different from mine and I'm curious to learn what made them so.