Libwebkit isn't actually chromium, it uses blink which is a fork of part of webkit. Understandable confusion though because webkit was part of kde, forked by safari, and then used by through chrome variants for a long time.

The rest of this comment is going to necessarily be nerdy Linux internals. sorry.

Unfortunately, I'm pretty sure chromium includes it inside it's binary and does provide or use any webkit libraries.

Orca uses it internally for it's browser so it won't start unless it has access to the library. When you build a Linux app it includes the name of the library which includes the ABI (basically the version). Newer Linux release include a different version.

You can see how that specific library stops appearing in Ubuntu releases https://packages.ubuntu.com/search?keywords=libwebkit2gtk-4.0-37

The new version is 6.0 I believe.

Appimage is one of the ways you get around this distro problem by including the versions of libraries. That's why they're so big. There are problems with that like how big the apps are stale bundled libraries with security issues but I digress.

Orca hasn't bundled webkit in the appimage and because of another problem/feature of appimage it falls back on the os library. Since new distros have dropped the older obsolete library version orca can't start.

That's a lot but I hope it explains the problem better.

I would like to help but my personal computer doesn't currently have enough memory to compile orca so back to just watching warning people it's a coming problem for them too.