They are backed by treasury bonds

Except when they aren't.

So many examples of stable coins just being a delayed rug-pull that collapses as soon as people pull out their money and it turns out that they aren't backed by anything at all.

At best they work like putting regular money in a bank. At worst they work like putting money in a "bank" but the bank is some shady anonymous dude from the internet with no oversight whatsoever.

You don't trust a bank because it could be mismanaged and greedy bankers could steal your money? Why on earth would you trust an anonymous rando more?

It's like those people who don't trust "big pharma" and instead eat supplements they bought from India via the internet by the kilogram.