@mr_harm@mastodon.social @libreoffice@fosstodon.org It puts you at the whim of MS. If MS change something in OOXML, everyone has to jump up and fix their implementation. Moreover, if MSOffice users send you a file which then doesn’t open properly in EuroOffice/OnlyOffice/LibreOffice then users will complain about “this new thing doesn’t work properly, why can’t we just use MSOffice like we always have?”. For sure, if ODF changes, everyone needs to update. But that’s the result of a public committee decision and there will be a standards document describing the spec - not reverse-engineering whatever Redmond have done unilaterally. If you default to a genuinely open spec like ODF, then in a couple of years when people are used to it, if an OOXML file doesn’t open, their instinct will be the at the sender is at fault, not them. And they’ll ask them to resend it in ODF. In 2026, there’s just no reason to use proprietary formats for things like standard productivity suites.