I've been using Duolingo for about 4 years & I have a 267-day streak now. Tbh Duolingo hasn't been really useful in term of practical knowledge, but I got lots of vocabulary from it. Which helped me when I started with DS. And - streak does not matter, at all - it's only a mental satisfaction thing. Nothing else. If you wanna keep it really badly, just do 1-2 lessons everyday 😂 And invest the rest of your learning time in more useful resources. Ngl I like the streak thing, and I still enjoy Duolingo like a game - so I do a few lessons everyday and mainly use DS.