I'm at over 3,200 days now :-)
I must say that the degree of enshitification over that period has been considerable!
Obviously I've been working on different languages throughout that period! And with different goals in mind for different languages, including for example as simple as understanding shop signs and simple interactions in the area I live which has many many Turkish speakers.
Finished quite a lot of the courses, though others I stopped part way through because they were so abysmal. Hungarian was one of those... which I had actually taken at university, and did it just to refresh my memory, but really it was just unusable.. Maybe they've changed it since (?)
There is, in my experience, one language that, if you learn it through Duolingo, you will be able to use with moderate competence. That is Esperanto. Which is of course an artificial language created over 100 years ago specifically to be easy to learn and use. But it does have the advantage that there are people all over the world who still learn and use it (and who also tend to be extremely encouraging and supportive as very very few people have it as a mother tongue - though they do exist- so they know what it's like to be a learner and not fluent).
I went through the whole course about two years back, went - fairly gingerly - to an Esperanto meet up in my home town, was actually able to communicate (!) and progressed from there in leaps and bounds. New people often come along to the meet ups who have also learnt ONLY via Duolingo, and yet we can communicate. Quite a lot say that it's the first time they've actually spoken it with others, and yet they can hold pretty sophisticated conversations.
Concentrating on Greek right now. Which is actually not bad. Despite them doing things like introducing 25 brand new verbs in a single lesson. But I'm really only getting a benefit in conjunction with LanguageTransfer, which is free and I can't praise enough, together with "Do You Speak Greek" on YouTube, and a grammar textbook.
Whenever I'm on a thread about Duolingo, I like to remind people that the grammar explanations they used to have as part of each course have been saved onto Duome, and that there is still a discussion forum there to ask about grammar, incomprehensible sentences, etc.
Long ago turned off/ignored all "reminders", animations, friend requests, sound effects, etc, on Duolingo, though I do appreciate that Duolingo offers different experiences to everyone, so if that is not an option open to you, my commiserations.
To actually answer your AIBU: you should use it to serve you. If it helps you, use it, if it doesn't, don't.
And all the rest, streaks, friends etc is merely guff to try to addict you. F... them :-)