There are also a lot of security concerns about Authy that were raised a while back. If you read the comments, it doesn't instill a lot of confidence in the team to implement a secure platform of this sort[0].
Unfortunately, security is one of the few areas in which 90% isn't "good enough" - all you need is one point of failure for an entire system to get compromised.
[0] https://news.ycombinator.com/item?id=4921684
