Many people act like it's only really language learning if you're learning all four domains (listening, speaking, reading, writing) and learning the language in the most efficient manner possible and for hours every day. However, the reasons behind learning a language may vary from person to person (or within the same person, as we're not limited to only one foreign language ever), and there can be value in learning a language at a pace on par with that of the humble snail, or mainly learning the aspects of a language that you're interested in. Language learning can be a hobby, too, not something solely for utility.
If you are a person who is just in it for the utility, there is nothing wrong with that, and maybe these tips would only be a hinderence to you, or maybe you will be able to find use of them, too.
There are those who hate Duolingo to the point of absurdity, treating it as if it is impossible to learn even a single thing from it, but it's really just a glorified flashcard app, with its own upsides and downsides. It is actually quite perfect for lazy language learning in many cases.