The majority of Linux distributions out there seem to be over-engineering their method of distribution. They are not giving us a new distribution of Linux. They are giving us an existing distribution of Linux, but with a different distribution of non-system software (like a different desktop environment or configuration of it)
In many cases, turning an installation of the base distribution used to the one they’re shipping is a matter of installing certain packages and setting some configurations. Why should the user be required to reinstall their whole OS for this?
It would be way more practical if those distributions are available as packages, preferably managed by the package manager itself. This is much easier for both the user and the developer.
Some developers may find it less satisfying to do this, and I don’t mean to force my opinion on anyone, but only suggesting that there’s an easier way to do this. Distributions should be changing things that aren’t easily doable without a system reinstall.
Some distros build their entire system as modules declaratively. NixOS and GUIX.
What has that to do with OPs consideration??
Not GP, but NixOS makes it easy to make new distros from a NixOS configuration, with ISOs and everything. See for example SnowflakeOS. This is IMO healthier than all the Arch clones etc., since all differences from the base OS are easy to spot, there is little duplication of effort, and it possible to revert to a base NixOS from e.g. SnowflakeOS if a user so would desire.