In reality the problem is more complicated and the issue is that the current media of teaching via worksheets and teachers is lacking and insufficient, which renders this debate obsolete. What you have is different parts, learning new stuff, practicing it, but also spaced repetition. Those need to be in balance with each other but also rely on cognitive overload, tiredness and motivation (among others) of the learner. So what you really need for a solution is software that replaces those work sheets and does a good job (as opposed to many of the current cheap learning apps) of giving you the right task at the right time. Eg. it knows that you have been drilling stuff and gotten good at it and so now its time for some more mixed stuff that could be paired with srs (stuff that needs refreshment). I think apps like kahn academy are good but could be improved and personally tried to build my own language learning flashcards app[0] after becoming frustrated with duolingo where I have a 2000 day streak.

0 - https://ling-academy.com/ It's a bit of a mess. I found that its pretty hard to build a language app.