question #2 Sahih al-Bukhari 7240, Book 94, Hadith 15 : Why did the Prophet Muhammad (ﷺ) refrain from making the use of siwak obligatory for his followers?

Allah’s Messenger (ﷺ) said, “Were I not afraid that it would be hard on my followers, I would order them to
use the siwak (as obligatory, for cleaning the teeth).