The same origin model is what enabled the web and apps to exist.

Without it, they would not be possible.

But the same origin model is also the original sin.

The same origin model separates every origin into its own isolated pocket universe.

Origins that have a critical mass of end user engagement will tend to accumulate more data in than they emit out.

This leads to a significant preferential attachment effect, where the biggest apps tend to get even bigger.

As a pocket universe gets more mass, it attracts ever more mass.

The same origin model is what leads to accelerated centralization and an inexorable pull towards massive, all-encompassing, one-size-fits-all software.