Database migrations are not hard when you have hardly any data, when you are still building something, and they aren't that hard unless you have enormous amount

Database migrations are not hard when you have hardly any data, when you are still building something, and they aren't that hard unless you have enormous amounts. On the other hand, having data where records have different attributes is annoying to have to handle everywhere at runtime, especially if it is because of something you have changed, and no new records are missing it. You just end up with code littered with handling of differences due to old design. This is, IMHO, not a good reason to use NoSQL.