Given the amount of people who ride around on them, their failure is probably negligible.
Get some thick heavy steel bars and feel safe
Now what other parts have you got on your bike?
For the reference I have a pair of ritchey prolite bars (retro, top end thin stuff bitd) for about. I had used them for quality riding back in the early 90's, thrown them on the ground (paper round), quarries, races, etc.. Well used. Then into gentle riding late 90's/turn century.
They developed a creak in the early 00's. That continued over the years, only used for commuting style of riding.
Roll on Retrobike I strip the bike and find a hairline crack going through the bar. Creak found, still it hadn't gone yet.
So they do go if they had a hard life and over time.
I still ride similar bars now of course.
Search on bar cracks for Aluminium and Carbon. Then Titanium and Steel.