it caused massive issues with performance
Performance is actually not the main reason we wanted to change the storage containers. I wrote a lengthy post about our reasoning here. In short, we want to make inventory management more convenient by increasing cabinet capacity so you wouldn't need to fill all the slots with storage containers to gain enough storage space for all your items. Another reason is that it wasn't intended that you could store as many as 2880 items per cabinet - that is getting reduced to a more sane number (although, a cabinet can still fit well over 1000 items).