Interesting. Getting rid of the demo would certainly reduce the Theme Site overhead.
But I have a number of fundamental objections to the Hugo Themes Directory and I am going to post them here in public.
Don’t you think that showcasing hundreds of Open Source themes by third party authors is too trusting?
What about theme quality? Is Open Source the only criteria?
There are plenty of reductive themes currently on the Showcase.
Also in the old repo the theme demo generation served as a check to see whether a theme complied with a minimum of guidelines.
The theme repo maintainers had to troubleshoot theme submissions and request changes or remove themes that went unmaintained and failed to build with the latest Hugo or themes that did not meet the repo guidelines.
This approach in the end proved to be a big burden for Theme repo maintainers but it was the only way to see if something was not as it was supposed to be.
(Anyway you should have a clear idea why I stopped being involved with the Themes repo last year.)
However moving forward I do think that there should be a complete rethink of the Themes Showcase.
Instead of its present form, it would be more manageable if it listed a few select community themes for specific use cases (eg. blog theme, portfolio etc), that should be created and maintained by the people who are members the Gohugoio GitHub organisation.
Like for example how the Wordpress team publishes official themes typically once per year.
This way these themes would also serve as a guide to templating and project structure practices.
Currently the only theme that sort of fits the above is the Ananke Theme that is used in the Official QuickStart Guide.
P.S. And pardon to all the theme authors I do not mean to alienate anyone but the current situation in the Hugo Themes Showcase is not manageable.