That's indeed the nicer way of paginating, but it breaks if the underlying resultset changes between requests. Which is exactly when cursor based pagination is generally used.
If the changes in the resultset are additive it's no problem as long as they are sorted in such a way as new results go to the end (which the api should at least make an option if possible). Updates to data within results may be a problem because you can end up with a dataset that has a view of the world that doesn't represent any particular time, but in many cases are safe. Deletions screw everything up and should be avoided if possible.
The general solution to this problem is to allow as part of the query some particular time that you want the results to reflect the state of the world as of, but that's obviously going to be expensive to serve.
