What happened to textbooks? or, Why are apps the go-to language learning option now?

I've noticed a trend towards apps and away from textbooks in the last several years:
- Beginning learners ask what app they should use, rather than what textbook/books
- The language learning shelf in bookstores has gotten smaller
- Language publishers transitioning textbook material to apps (e.g. Assimil)

What does everyone think about this?

Are there more casual learners that don't have time for textbooks? Are beginner language learners even considering textbooks as an option? Do the learners that start on apps transition to textbooks later or are apps enough to get you to an independent stage where you can progress to native materials?

Personally I still look for a textbook when starting a new language as I don't believe an app can get as indepth but I do use apps for supplementary learning. Even past the beginning stage I still buy books and textbooks for intermediate/advanced learning.