Traditionally backups of most *.tiki.org sites were centralized in a bkp.tiki.org server in amse2, but it seems to have been discontinued at some point during 2019.
Some other backups where handled in a decentralized way using Syncthing by several tiki project admins (those who voluntarily offered to learn how to help and shared their own Tb of disk space).
Lastly, some sites where backup up elsewhere by their own sysadmins (composer, show, show2, r, etc)
That requires that project admins share disk space with their own resources to hold copies of most (all?) *.t.o sites. Therefore, no money would be needed to the central project funds to get the solution started/situation improved.
In the meantime, see:
From devices being in a decentralized network
To be continued