But that is relative. Of course if you spend ten minutes a day you will have a smaller progress. But still you make steady progress. It took me two month now with Spanish to get from nada to being able to say how many siblings i have, where my parents are from, where i live and what job i have. It is not much, but last week i didn’t know how to express my workplace and by next week i’ll be able to express something more.

This is the same like for everything you learn or train. You want to be a concert violinist? Yeah better practice multiple hours a day. But just practicising ten minutes a day will still get you to be a decent player after a few years. Want to look like Schwarzenegger in his best times? You got to hit the gym regularly and on a proper plan and diet. You just want to be fit and build some muscles? Ten minutes of planks, pushups and situps and you’ll notice your shape changing after a few weeks.

As you said, with the small steady work you’ll hit a wall eventually, be it languages, physical training or instruments. And then you need to put more effort for really filling the gaps.