Memrise is pretty good (or was, when I used it years ago). Much more serious, less gamified.

I found Babbel's lessons to be very helpful, they do a good job actually explaining the rules of things to you, but they have a smaller selection of languages to learn and I believe they only have a brief free trial; there's otherwise no free tier.

For Japanese: Wanikani (for Kanji) and Bunpro (for grammar); nhkeasier.com for reading material. Ideally also get an Anki deck that complements Wanikani for other vocabulary.

Different people learn different ways, so there's not one answer.

I think my main recommendations to consider over duolingo though are actual language textbooks, and then using any flashcard program for the information you need to memorize in the textbook (mainly vocab).

I think another strong contender is taking classes, either locally or online, and getting to the point where you can consume media in the target language as soon as possible, even if it's children's books

I subscribed to lingq.com and am loving it. It is a content app as opposed to a traditional language learning app. They have a bunch of content for you to read in your target language (particularly their mini-stories) and you can import news articles or ebooks to read yourself. You can tap any word and get a translation and then practice words you don't know from a chapter or overall. The theory is that just lots of exposure is better than vocab drills and I tend to agree. Some guided learning (a bit of grammar here and there) is helpful but for the most part as long as you aren't a complete beginner content is where its at IMO.

1. Get a tutor for the basics, spend at least 1-2 hours learning every day. Have a good sleep. After the fundamentals, get on one of those platforms where you speak for 30 minutes in your mother tongue with someone else and vice versa to practice.

2. Move to a foreign country (this is how I learned 2 languages, without knowing how - just pure daily exposure).

It doesn't suck per say... it comes down to the course and your own interest in learning a language. To me Duolingo worked well as an entry barrier for getting started, the app interface is polished and the gamification aspects makes it enjoyable and sometimes pushes you do to a bit more than you'd otherwise have done.

I've been doing the Japanese course for 2 years continuously, during the first year I only used Duolingo but as I progressed and became better at understanding the basics, I sought other apps for the things that Duolingo lacked. nowadays I use 'renshuu' as well for getting a deeper understanding of some areas, and 'kanjigarden' to learn all the various kanji that one can bump into.

Last but not least, I also use Takoboto as a dictionary to regularly look up stuff that's not well explained.

Refold method, probably. The decks are pay-what-you-want. It was developed by language learning junkies: they stole the main, widely-accepted strategies for learning a new language as quickly as possible from language learning forums, then formalized it and kinda productized the thing.

The gist is that the past decade or two they figured out that you learn a language fastest by focusing 100% on comprehension for your first 6 months or so, and only starting to read and write after your comprehension crosses a certain threshold. You basically race up to the point where you can understand ~70% of a TV show, then from there, learning to read and write is easy.

I don't think it sucks, it's just over used in my opinion. Once a person completes the course, they should challenge themselves more, like trying interlinear reading.

Use Duolingo and combine it with other methods as you feel like. Eventually you will come across one you actually like. Duolingo is good for keeping you in and for slowly teaching you basics.

Once you are on basic level, start watching netfix shows in your target language with subtitles. Or youtube videos in that language.

Anki. You'll learn so much quicker