The idea is that as soon as you begin to write a hashtag on a review, a dropdown appears under it that shows "popular" hashtags that also start that way, filling out what you have already written.
They could be organized from more popularity to least, that being most searches to least, or if doing it that way is too difficult, from most results to least. It would be even better if it showed the number of searches/results next to each suggested hashtag.
This is done on many websites and apps, so I think it shouldn't be a problem to add this to Maps.
With this implemented, users would know which hashtag would reach more people and also make their review even more helpful. It would also provide some level of standardization.
Here's an example on how it would work:
The user begins to write #d
The list appears, showing many results
The user continues writing, and has now written #donu
In the dropdown list, they see that #donuts is more popular than #donut
The user writes #donuts, or clicks on that option on the list.
If you have any other idea regarding how to solve this problem, or improvements on my idea, please comment them!
I have already written two other ideas about hashtags, if you're interested in them feel free to click on the links and check them out: