Good grief!
There was a time when fgets did not exist.
And people said, "gets works."
Now, the more enlightened say it doesn't.
It works under certain conditions. It does not work under other conditions.
Is it safe?
Well, as long as there are hackers out there who have nothing better to do than to break the 1's and 0's of a novice programmer, then there might be a small percentage of instances in the life of gets where gets does not work.
Other than that, I just don't get your logic.