everything is possible in excel… someone wrote a DOOM clone in excel.
I once worked at a company where someone hacked together a PO generating tool in excel 10 years prior and it just kind of stuck around even though the company grew into a billion dollar market cap public company
I feel like what you described should be a big fat warning on the nextcloud page
OP is a lot more gracious than most internet users by accepting some responsibility. But i wouldnt blame them. I might have done the same, and i’ve been self hosting nextcloud for 8 years now.