If you are wondering why the scientific community is now very anxious about #Pubmed being offline, it is not so much that the papers will be lost, they are with the publishers ultimately (there's am access discussion to have there as well).
Although the open access copy that were stored at Pubmed central are not accessible.
Now, if #Pubmed is taken offline entirely, that would suck, we would probably all head over to #EuropePMC (we should) and EuropePMC would have to make a few adaptations, mirroring is not going to be enough anymore, they'll have to take the lead.
But if we're being honest, the worse that can happen is probably that #Pubmed comes back purged of the literature from certain topics.
Imagine Google not returning any results for anything related to, let's say, vaccine research, development or manufacturing except maybe some retracted papers stating that vaccines are dangerous.
Sure, people could still look on Bing, but if Google is still there and it is not immediately visible that it is missing something, most people would still use it. In the case of #Pubmed, you'd effectively slow down research on this topic, worldwide.