I have worked for 2 companies that closed. One company I still have the contact information for one of the former employees (who is now retired and not in all that good of health), who will vouch for me. I also have a website I can refer people to, which I built, but of one of the subsidiary companies.
The other, I have no contact or ability to contact, as the person who ran it disappeared without a trace. I have physical samples of the work I did in the form of newspapers. But eventually I'm going to run out of them or have to throw them out due to age. The website DOES show up on the waybackmachine, but not the downloads (you can see the page, but can't download anything)
At day's end I can say what I like, but if i have no proof, how will I be able to get a job, or if i DO get hired stay hired due to not having direct proof of prior work history?