Seems like a catchy title and super short paragraphs might be the bigger reason this article got a lot of traction... but I do agree with the premise. It's exactly my approach to speaking Spanish and I'm MUCH better today than I was two years ago, and the 20-30 minute effort I make every day doesn't stress me out or bother me so it's been very sustainable.
For something like "getting better at writing" the one percent rule feels a bit more abstract because improving at writing is isn't the same as memorizing vocab. If you really want to improve at the craft, writing a bunch is key... but so is reading a lot, so is getting direct feedback, so is studying the subject itself, and a dozen other things. Make sure you're spending your time well when it comes to sharpening your sword (read: pen) because if you just write another life update blog or food review and it's a rinse and repeat of what you already know... you're likely not really improving very much.
Going to work and spending the money you earn on your life and breaking even at the end of the year is just existing... its doesn't make the time at work "productive" if you're not moving forward in any meaningful way.