Consider what a transporter has to do... convert every molecule of a person into energy, and then reassemble them so precisely that even the energy patterns in their brain are identical.
It's amazing that it works at all.
It's even more amazing that it works as often as it does.
And that people routinely rely on it.
Something to think abut:
Consider what a car has to do... convert fuel into energy in an internal combustion engine, and then hurl people at speeds multiple times that of a horses running speed down a lane only narrow enough for a few feet on either sides of the vehicle.
If you lived in a time before cars, it's amazing that such a concept works at all.
It's even more amazing that it works as often as it does.
And that people routinely rely on it.
My conclusion is that transporters, like cars or trains or planes even, are safe enough that people use them routinely enough that it is the norm, in spite of any accidents (possibly as many as in the case of cars, which is hundreds per year).