The longer the supply chain, to get from raw atoms to physical product in your hands (in the case of a SaaS, from raw bits to a digital product in your browser) the easier it is for a company to wash their hands of a problem.
“Oh, that wasn’t our fault, that was a supplier.”
Abdicating responsibility for something bad happening to a vendor or supplier means you don’t have any legitimate claim on taking credit when it all goes right.
Own the problem (we let bad quality slip in to our product), and show what you are doing to fix the problem (change supplier), and make every effort to show that you have fixed the problem (transparency).
But don’t ever pass the problem down the supply chain with no attempt to resolve it yourself.