The app suggests to use tags to quickly sign a transaction. For me personally it helps to spend more intentionally and makes it easier to retro my spending in the end of month.
When using hashtags, it would be helpful to get a drop down list with previously used hashtags to tag transactions faster. Now this functionality is absent and hashtags don’t really have any purpose.
This was mentioned many years ago, so there may be an existing thread you could add your vote to, but don’t hold your breath that it will actually be implemented.