Guys are never going to hit against the shift without other rule changes. Analytics strongly, strongly discourage it. So there HAS to be a rule change of some sort.
The other options besides shift banning would be to...
1. Move back LF and RF outfield fences (too expensive, people seem to hate it when it has been done e.g. Baltimore).
2. Deaden the baseball (tried it, caused too big of a decline in offense).
3. Adjust the height or distance of the pitchers mound (still might happen eventually, but is more controversial than shift banning).