We're using the app router, and deep in the client code, we determine the title for the page. The user can also change the title. Ideally we would be able to set it here with a <Title> tag.
Instead it seems like people are suggesting using document.title? Notably, we cannot use generateMetadata as the title will change, and we can only load the data on the client side.

Setting document.title seems a bit fraught with errors, as you could run into issues when navigation is happening and different pages are setting to the title simultaneously.