Anecdotally, this has not been the case for me.
Similar to the parent, I have accelerated my learning tenfold by ditching D**** in favor of reading, watching, and listening to content in my target language as well as speaking to a tutor I found online.
I've wasted a tremendous amount of time going through and ultimately completing a tree only to find myself crossing the finish line not being comfortable saying anything in that language. Is that a criticism of me? Perhaps. But, the big D once fooled me into thinking the answer to that question was that it is. Which is to say, I don't believe it's a criticism of me.
In the beginning I thought it was excellent and that’s why I kept coming back.
I tried it again the last 12 months and the app wasted so much of my time making me skip through promotions and do-nothing animations. Opening chests, collecting gems, all the gamified stuff.
I didn’t need it. I was already self motivated to learn without a bunch of time sinking doodads that you have to click through.
I guess duolingo is good if you are struggling with motivation.
Recently I used a paid app called Pimsleur that I liked. There’s also a lot of good free resources on YT
It would be awful if I was forced to wait for the animation to complete, which fortunately, they do not. The same applies to basically all the animations except for the opening screen.