The appeal of Google Slides templates is not only visual convenience. A team can duplicate a file, assign slides, leave comments, and watch changes appear. The format succeeds because participation is distributed among people with familiar controls. For many internal decks, that social workflow is more important than advanced composition.
An HTML presentation makes collaboration less synchronous and more mediated. Stakeholders review a browser result or source change, then an author or AI agent integrates the feedback. This can produce stronger system-level consistency because one implementation layer controls the deck. It can also create a bottleneck if reviewers expect to fix wording and move elements directly.
The decision is not collaboration versus no collaboration. It is collaboration inside the canvas versus collaboration around an artifact. htmlslides is useful when browser-native presentation and distribution justify the latter. It should not be positioned as a hidden Google editor, and its templates do not provide native Google Slides files.