Offset vs Cursor Pagination
I'm not surprised at your results, bar a few minor details that any decent database will optimize away your implementations are the same. You are also basically just re-implementing the find_each method. 

Note, you might find a real difference if you used database cursors but that is a completely different thing.

The real difference between the two is that cursor based pagination responds better when the underlying data changes. i.e. using offset based pagination you might have a record included twice or skipped if a record is inserted or deleted by another process.