> All of our tools having silos of data and only having difficult to implement one-to-one integrations seems broken- it does not feel like it has to be this way as part of the nature of the software.

The problem is completely self-inflicted and caused by greed. It isn't difficult to make software interoperable - you actually have to work hard to make it non-interoperating. Which is precisely what aforementioned companies did by creating data siloses exporting just tightly-controlled APIs, guarded by ToSes preventing interop from happen organically. SaaS companies broke interoperability on purpose.