There are a number of questions on this site asking essentially the same question:
Why do 2FA apps send an SMS to the user rather than have the user send an SMS to the server?
here are some examples:
- [3 votes] SMS Verification Code vs. Response Message. Top answer: 3 votes. Flagged as possible duplicate of (2).
- [25 votes] Why do apps with phone verification send the user a message, rather than have the user send one to them?. Top answer: 80 votes. Flagged as duplicate of (3).
- [3 votes] Why not authenticate with the user sending an SMS?. Top answer: 3 votes. Flagged as possible duplicate of (2), but vote looks like it failed.
It seems weird that a post with 25 / 80 upvotes is marked as a duplicate and pointing to a post with 3/3 votes.
Moderators: Can we flip the dupe flag so that (3) points to (2) ?
(Thanks to @AndrolGenhald for pointing this out)