Your understanding is just outright wrong. The `apt` command has an unstable interface so that it can improve the CLI without worrying about breaking scripts. The `apt-get` command is the stable interface for scripts. `apt` was created after `apt-get` became ossified
exactly because the developers work hard to keep the interface for scripts stable.
> In fact they themselves tell you that their commands are not stable and should not be used for scripting, despite no alternative mode or application existing.
No, that's just the apt command, not the apt-get command, and the manpage for apt tells you exactly how to do this instead. It's clearly documented, so your "despite no alternative mode or application existing" claim is simply ignorant.
Please read the documentation and learn how to use the tooling before criticizing it and misleading others with claims that are outright wrong.