Writing code every day doesn't necessarily mean doing more than a few short lines. I like to think of it as a mental exercise, like how solving puzzles every day helps you think better. Also, there are days where I have kept a streak just by documenting something or writing up issues of a repository, which are things that don't involve programming but are still useful skill related to programming (and are much more relaxed than havong to write 100 lines of code for some project).