Can you learn another language by playing Scrabble?
Yes. Playing games like Scrabble can help you learn any language -if that language has a scrabble version- and improve your vocabulary. However, you can primarily benefit from scrabble by increasing your vocabulary. Obviously, you’ll need other resources for other language skills.
So with playing scrabble, you won’t reach fluency because it is only a small tool that teaches you more words. Also, if you play scrabble online, some apps allow you to connect with native speakers and learn from them.