In order to achieve certain customizations, some core blocks were partially overridden, by runtime replacing some of the React components the blocks use. This was to get around limitations of WordPress at the time.

Most, if not all, of these customizations can be achieved without a code override in the current WordPress version. Mostly using theme.json, to control which sidebar controls are available per block type.

The relevant config options were only added to WordPress after these overrides were created.

Since this is replacing parts of recent WordPress code with a modified, older version of the same code, it needs to be checked and possibly updated on every WordPress upgrade.

We're likely also missing out on newly added features to the parts we're replacing.