Sprint goal is not about increment but its value
There are lot of questions in the agile community about how to frame a sprint goal. It can't be like 'completion of all items in sprint backlog' or when working on stories which are part of different features/applications, it can't be like 'enabling the search filter facility plus adding a new product to ecommerce category and so on..'
The reason for confusion is I think we are trying to tag the sprint goal to 'what' part of the sprint and not to the 'why' part. Why is this sprint valuable ? whats the goal to achieve and why? So the goal could be target increase in value to the product?(how the value is measured is upto your organisation). Increase in customer base by 10% or solving the long pending problem in some business process ? Thats what stakeholders need right ?. Product Owner explains how the increment could increase the value. So the team collaborates to define Sprint goal to achieve the desired value.