If you are like me, your development Rails BD is for fudging some data. Even if not everything is perfect like my production database, I try to not insert so much junk data so I can at least control my development expectations.
By using FactoryBot or plain RoR you can create in memory object and run the very nice ActionMailer::Preview tool in the development version of RoR. This will save you tons of time if you have to adjust HTML and CSS.
But what about a view that require a BD access ? This happen to me as I need a table to present some user information from the database.
If you use create or FactoryBot.create you'll end up with a lot of records in your BD that you don't really need.
The question then is how to manage a cleanup of the data after the previewer run?