The Mods installer hasn't been improved in years and it's unlikely someone will step up.
Mods installer can't work in some places because of file permissions
For themes, download links are provided at themes.tiki.org pointing to the theme archive at the Sourceforge repository, for people that can't install via the mods admin. But this entails downloading and then uploading the files so is more trouble than an installation via mods admin or profiles.
One thing the mods are used for fairly actively is themes that can't be included in the Tiki package due to license conflicts. On the theme creation/maintenance side, it has been good to use SVN for the versioning function. I hope this would continue with profiles (via wiki history?) or be improved, as there is a lot of redundancy in the current system (full set of files for each theme for each Tiki version, even though sometimes there is little change).
Mods is a packaging/distribution tool for files managed in a SCM (SVN). Instead, profiles could be used to deploy and wiki pages could become the SCM, with a nice Web-based source code editor
The license of the content can be GPL because the user installs themselves
Contributors can contribute via the browser (especially interesting for translators)
We would be using maintained code
Regarding themes, module configuration is an increasingly important aspect of theme-specific layout and function, and so it would be great to use a profile to apply the module configuration of a new theme. If this profile could also contain or enable the transfer of CSS files and background images, etc., that would nicely put everything in the same installation process.