I think it is possible to build infrastructure that will allow entities to spread responsibility. They do it in other fields I think?
For example I can’t imagine Ford checks literally every single individual component that gets put in their cars, right? I assume they have contracts and standards with manufacturers that make the parts, probably including random spot checks, but at some point to handle complexity it is necessary to trust/offload responsibility on some suppliers.
I bet you could get those sort of guarantees from, like, Intel or IBM if people generally were willing to pay them enough (can you now? Not sure, probably depends on the specific package). But nobody would make that sort of promise for free. The transparency of the open source ecosystem is an alternative to that sort of thing, no promises but you can check everything.
Just to be explicit (since I’m sure this looks like needless pedantry), I think it is important to remember that the open source and free software ecosystems are an active rejection of that sort of liability management framework, because that’s the only way to get contributions from a community of volunteers.