With all the innovations Bass boats have made, I am SHOCKED they are still in the stone ages when it comes to keeping Bass alive in those antiquated livewells. If Striper fishermen can keep a tank full of delicate bait fish alive on a summer day then Bass boats should be able to design systems to keep five Bass in great shape. I am sure many of the same rules could apply.
Keep the water a few degrees cooler than the lake temp. Maybe add a temp gauge to warn if the livewell temp is approaching the lake temp. Add something to the water to make it slightly more dense which helps the water to hold dissolved oxygen. We use salt. Lots of stuff could work. Add an air system to the livewells. It doesn't have to be oxygen and it's better if its just air just as long as the bubbles are as small as possible (small bubbles help remove carbon dioxide from the water). Insulate the livewell and use a closed system. Add something to block ammonia if needed or change out some of the water just a few times during the day then bring it back to the desired temp.

It isn't rocket science keeping fish alive in a boat and bass are actually much more hardy than most fish. If you strictly leave it up to weekend warriors then get used to this pic. Make it more idiot proof and you will see better results.