Archiving data

Good morning, I have question regarding the best way to ensure that data is accessible once archived. My feeling is that exporting data into Excel format is better than CSV b/c the relationship to headers would be better than CSV.
Not sure if anyone can confirm this or provide more insight.

Thanks,
Manon Miron
(she, her | elle)

Manager, Digital Accessibility and Product Development (DAPD)
Digital Transformation Branch /Health Canada and Public Health Agency of Canada
manon.miron@ hc-sc.gc.ca / Tel: (343)551-1965

Gestionnaire, Accessibilité et développement des produits numériques (ADPN)
Direction générale de la transformation numérique / Santé Canada et Agence de la santé publique du Canada
manon.miron@ hc-sc.gc.ca / Tél. : (343)551-1965