John Mueller from Google posted a mindful and useful response on Reddit mostly around where to start with hreflang. He said “It’s easy to dig into endless pits of complexity with hreflang.” “My recommendation would be first to limit the number of pages you create to those that are absolutely critical & valuable,” he added.

After you go through that thought process, then he said “focus first on pages where you’re seeing wrong-language traffic.”

So it doesn’t always make sense to simply deploy hreflang everywhere because it might be easier to not think about it. “Sometimes the balance between “save effort by thinking” and “just do it everywhere” is not that straightforward to determine,” John Mueller said.

Here is his full response:

Forum discussion at Reddit.