The problem is, decision-makers will not go for the "secure" way, they want a solution out of "one mold" - and so do users. It is a common complaint when trying to set up a FOSS solution, users complain that they have to learn and memorize different ways of doing the same thing across different application... and made worse by many FOSS projects not having UI/UX designers at all that care about consistency even in the scope of the application itself.
And on top of that, many data exchange formats are not just "old", they're "fossil" and don't even come close to meeting the demands that people have come to expect.
In every single company I have been working in the last 15 years, information was spread across so many different tools that integration was a moot point: Office365, Jira, Confluence, a separate ticketing tool, some mkdocs or single markdown files in repositories, spreadsheets, dedicated HR web portal, intranet, internal blog/comm/social media... Even within Office365 information is stored randomly as office files in sharepoint, teams channels, personnal onedrive, emails, copy/paste in teams, teams channel onedrive synched drivees, onenotes...[1] Also RBAC makes sure that whenever you came across one doc containing link to other stuff, you end up having no access to half of the links
Bottom line the tightest integration doesn't reduce any friction because there is not a single toolsuite that fits every use case and people end up making a mess of everything. You never know where you can find the information and every single teams wiki ends up being a collection of links to a myriad of different places. Also half of the people still email people documents instead of the links because they don't understand anything else.
[1] yes it is in the background the same product but people access them and more importantly know or search the information in totally different ways.
And on top of that, many data exchange formats are not just "old", they're "fossil" and don't even come close to meeting the demands that people have come to expect.