Telegram has such a good UX, like really good. Using as many devices as you want is a breeze, having multiple accounts on the same device. Their bots API is so easy to use.

Yes, it's at the expense of security perhaps... But I tried to get my wife to use Signal, as well as many friends and it never stuck bar one or two. She had to use telegram to contact someone and decided she liked it and continued using it.

It is what it is.