I think Signal shot themselves squarely in the dick by removing SMS functionality.
Previously, you could use Signal as the primary SMS/messenger app. Any conversations with other Signal clients secure. Conversations in SMS/MMS? Marked as not-secure.
But, out of some purity concerns, SMS functionality was removed and the dev team focused on adding useless shit like “stickers” and then the pin-code harassment.
Signal adoption plummeted as intended (?)
They figured out how to resolve it weeks ago.
It has taken this long to implement the results, and to get usable data flowing again