Every time Duolingo comes up, people express their weird standard for it: If it can't take you all the way, it's useless. Which applies to literally every method for learning a language.
And when you press someone on their alternatives to Duolingo, most of the criticism falls apart. The OP's pitched alternative is a classroom where the teacher points down and says "this is a table"? That doesn't compete with an app I'm using on the metro.
Another alternative people pitch is consuming content in the language, something I was able to do after using Duolingo (read the news).
No, it is because Duolingo is an addictive trap optimized for "engagement" (not learning) that requires you an absurd amount of time to progress very little, because it is explicitly designed to be ineffective with the looks of being effective (that's how they make money).
Want alternatives? Among apps, LingQ, for example, or LanguageTransfer. Among not apps, Lonely Planet phrasebooks and StoryLearning graded readers.
There are really many good options if one bothers to search.
That was simply an example of what's actually used in schools teaching adult immigrants of all ages! It was not something I pitched as an alternative to Duolingo. (Though it must be said that this particular school I mentioned has a very good track record in churning out able speakers, though this is not something a casual learner would want to try. It's basically full time. Very, very hard.)
For language learning there are more good options now than ever before. Not all of them are equally good for everyone, we're all different after all. I, for example, have always been utterly unable to learn by memorizing stuff (word lists or whatever), but I know people doing the exact same who can actually transfer that to active use. I never could. On the other hand I'm good at learning by reading and listening to input, as long as I can get the gist of it. I learned Italian to a survival level by first using phrasebooks so that I could book hotels and order food, and at the same time I listened to people for hours every day, for weeks and months at the time (because I was surrounded by people). Then I came across a shelf chock full of Peanut comics, in Italian. Ideal material. You see the story, you read the text, you understand what they're most probably saying, and after a shelf-meter of that I had grasped quite complex Italian grammar (some of which doesn't exist in my native language). Then I continued with Calvin and Hobbes books, with text in addition to the actual comics, and then newspapers and books. And all the time listening, and speaking with people in shops and elsewhere. That's an approach which works for me. This was all before Youtube and net resources.
Now there are so many options.. at least for popular languages. Graded input is what I would recommend. What's more important than anything is that it's interesting. And it's important not to fall in the trap of learning about a language instead of actually learning the language. The former is easy, and interesting.. but won't teach you the language.
I just wrote this in another comment, but the hardest part of language learning is the daily practice.
Learning how the language works is the easy part. But only through the daily practice part do you develop the skills to read, write, and speak on the fly.
So the question comes down to: what are you willing to do every day to get that practice in? Especially when you're a noob well under the level needed to do (or stay interested in) more interesting things like read the news.
That's what Duolingo helps people with. And it's already compatible with the things you mention, like reading comics.
You might be falling into the trap of looking at people who aren't motivated to do anything but use one app on their phone and then pretending they'd otherwise have the motivation to learn through an ideal you have that requires more motivation.
When I started Duolingo I didn't even see myself as someone who would or could learn a language, so trying to read comics in Spanish was never on the table (much less a phrasebook, ugh), not an alternative that Duolingo was shutting down. Yet after months I realized I could incidentally read BBC Mundo. I'd wager most people are in this camp since Duolingo is such a "might as well" opportunity very much unlike your proposed alternatives where you assume everyone is super motivated.
And when you press someone on their alternatives to Duolingo, most of the criticism falls apart. The OP's pitched alternative is a classroom where the teacher points down and says "this is a table"? That doesn't compete with an app I'm using on the metro.
Another alternative people pitch is consuming content in the language, something I was able to do after using Duolingo (read the news).