The main legislative issue in America is corruption: good laws that fail due to unrelated, bad amendments attached. If every bill introduced in either and both houses of Congress were single purpose only, this would close the loopholes of back room deal-making and each bill would pass or fail based upon its own merit.
For example, there could not be a good school protection act that fails because an unrelated 50% fuel tax increase was written in as an amendment. This would require a separate bill for each. Any Congressperson adding, in any way, any subject unrelated to the spirit and scope of the original bill would first face censure with their language removed from the bill- then full expulsion if done a second time- with no option to ever run for any government position in the future.