Evidence is still needed. Safety and efficacy are still required. But how and why those happened doesn't have to be as strict. Where the drug came from, how it was made, etc.
The FDA already did it once with the COVID vaccine. It skipped or rushed almost the entire process and it turned out mostly fine. But anything else it asks for everything, down to the minutiae like how many seconds did the cells get thawed out or excessive requirements like proving production quality can remain stable for months while a drug batch is produced in only 2-3 weeks.
The FDA basically say drugs has to be produced in their way and their way only. Any deviation or attempt to try something new carries too much risk of rejection. Following their way usually give good results. But not everything can be forced into that narrow path, especially for something like biologics that involve living cells. Even something as tried and true like a mAb still routinely get rejected internally because the cells producing it simply can't keep making them without some additives that are either too expensive or not yet approved for the current process. Biology is messy and it isn't easy getting things to work even when they are supposed to work, so making something "new" to work in a specific way is too risky. That is my point.