I use duolingo for language learning. The beauty of the streak feature is that you can do as little as 2 or 3 minutes to keep your streak going. It gets you in the habit of doing something every day, even when you don't have time. Your streak feature requires 10 questions that can take a lot of time -- too much on a busy day. Although that amount is ideal, it doesn't work because the streak is unsustainable. Instead, make it so that one question answered kept the streak going, and maybe a different color if you do all 10 questions.
Thanks for your suggestion! We completely agree that building a daily habit is key to long-term success. The good news is that our streak feature already works the way you’re describing—answering just one question per day is enough to keep your streak going! We appreciate the idea of visually differentiating between a "full" study session and a minimal effort day, and we’ll share that with our team for consideration. Thanks again for your feedback, and we’re glad to hear you’re making studying a daily habit!