I can say that this exact page as it is now, is exactly the reason they most likely got purged - also that this isn't helping with the situation but doing the opposite.
Artwork archive is great idea and many artists do this kind of stuff, I absolutely love it especially when it's on platforms where you can leave tip before downloading, it doesn't mean you have to do this kind of stuff as last resort, it's great idea to have in general.
Also invest in NAS to backup your stuff, remember the 3-2-1 backup strategy, never solely rely on anything, were it your local hard drive or booru website on the internet.