Most browsers record every change in the global history regardless of whether `history.pushState` or `history.replaceState` is used. The HTML Spec[0] is explicit about session history but does not define how global history should behave.
I can understand why the spec makes no mention of this -- global history is a user-facing UI feature, similar to address bar autocomplete, and it makes sense for browsers to control this behavior. That said, I'm always annoyed when I look into my history tab after visiting a page like this (e.g. Vercel Domains[1]), and see my global history flooded with entries for each individual keystroke I've made, all in the name of "user experience".
In this particular case, it's just a fun gimmick, but for everyday websites I'd much prefer if they just debounced the updates to the URL to avoid cluttering the global history.
[0]: https://html.spec.whatwg.org/#navigation-and-session-history
Is there a way to update the URL (ie: keeping it reactive in the address bar) without creating those history entries, or to ask the browser to squash the last entry it created into the previous one?
[1] https://nuqs.dev
Since there's no spec for global history and it's unlikely one will be introduced, the most practical solution to avoid flooding the browser history would be to debounce the changes.
This is the approach taken by Google Maps -- with maps being a well-known case where URL updates would clutter the history, as noted in the Bugzilla report.