How dangerous is it to drive with bad bearings?

[Nevada_545]

@Clueless33

I wonder why the left rear tire worn down so negatively ? Any ideas ?

Are all the tires of the same age?

@Clueless33

I replaced 3 tires last year and one this year ( last week ) and I was told the tires that were replaced last year have about 6/32 tread left.