I think teaching yourself to learn autonomously is one of the richest parts of the experience. Yes it can be frustrating at times. Yes, as you mentioned you will get "burned" by misallocating time to the wrong resources. But trial and error is always what helped me innovate new processes that I can share with others.

A huge advantage of taking a more independent study path (supplemented with speaking lessons of course) is the ability to grow confidence and self-worth by surmounting these challenges.

It's more up to the learner to decide their level of autonomy when approaching a language. When I'm learning a language autonomously, I like to have Finnish teachers as mentors. But even with them, I push back against some of their advice, such as wanting to teach me the written language instead of the spoken language.

You wrote a great article! I just think there are a lot more nuances that are worth exploring than saying autonomous learning will work for few learners.