On an Android phone you don’t have to blank the entire phone. You can go into Settings>Accounts and delete your Google account. This will immediately remove your gmail/calendar/contacts/Google Drive/Fit/location info/etc — pretty much everything except your texts. Then just remove whatever SMS app Dropbox and you should be good to go, no?
The exception of course is if you use a lot of third-party apps like Slack, Whatsapp, etc, which I do not. Only third-party one I use that would be problematic is Runtastic, which can track your movements, and which you may want to delete.
Following this method will vastly increase the time it takes you to reinstall. You simply go into the Accounts setting again and give it your username and password and the data will re-download.