Redbacks are close to harmless!! They rarely bite, and to most people they are no worse than an ant bite.
As for their reputation of deadly, only if you had a reaction and did not seek medical attention for a month!!
I read somewhere there has only been 2 deaths since an antivenom was developed in the 60's?!
We have pet ones in every corner of our garden sheds in WA, you leave them alone, they leave you alone.