That's not better than Duolingo, no.
Duolingo is OK initially (especially if you need to learn a new alphabet), but then quickly move on to
* https://www.languagetransfer.org/ (will give you a good understanding of the principles of the language but without feeling like a grammar book)
* https://www.pimsleur.com/ or similar audio courses (expensive, but thorough, seem to be informed by spaced repetition principles, I remember what I learn here)
* and when you've got the basics down, slow speaking podcasts or youtube which will increase your vocab and understanding greatly
* lots of youtube/netflix (use https://addons.mozilla.org/fy-NL/firefox/addon/youtube-dual-... or one of the many addons that give more control over subtitles, eventually only foreign subtitles or none)
* simple translated stories (I don't know what these are called, but you'll typically have first a story with translations interspersed, then the full story without any guide). https://www.lingq.com/en/ is a site that does this for you, though I guess you can use llm's this way too now
You want lots of input. You also want some deliberate practice making sentences, though in smaller portions than the input.