If the reusable bags lose their vacuum due to de-gassing and it is true that carbon dioxide is used as a preservative (which it is) then this might not be as much of an issue as thought, particularly if you are not freezing and using disposable vacuum bags. You can re-vacuum in both cases.
The issue is obviously air getting in, rather than de-gassing from the inside. How you would identify that I don’t know, doesn’t seem possible for the normal person.
So maybe, depending on ones thoughts about CO2, vacuum bags aren’t such a bad idea.