I would guess adding laterals would be more productive, but that would be a question for the folks with geology knowledge.
Initial (ca. 2002) multi-lateral wells were on one section (640 acre) leases, and went corner to corner, then we cut windows in the casing and drilled down the section lines from the same vertical wellbore.
That left some significant gaps in production, especially in a tight formation where you did not control where the frac went in the formation.
Longer laterals became more commonplace as the shift went from 640 to 1280 acre (two section) leases (ca. 2004), but these left a lot of formation some distance from the wellbore, so it raised questions of how effective reservoir drainage really was. (It did save money on rig moves, drilling vertical wellbores, and casing).
Now, with pad wells (ca. 2012), there are 4 wellbores (per formation), about 1250 feet apart, running some 9500 ft. down the length of the lease, which can be perforated and fracced in stages, with sections of the wellbore sealed off outside the liner by swelling packers to help control frac propagation.
The result is far more efficient reservoir drainage, at much less cost than drilling individual wells on separate locations.