Why is my EFI so big?

I’m having a little trouble. I don’t want my EFI to be so huge? If I have an extra 209gb I wanna be able to use it.

I upgraded from Catalina to Sequoia through Legacy patcher.

It’s a mid 2015 MacBook Pro A1398 with a i7 16 gb ram and 15in if any of this matters. I looked online and saw that Apple changed how the storage is set up where I have two HD’s one is for system stuff and the other is for user data. I know it’s not actually two different HD’s. I’m just not sure what EFI is or why it’s so huge. Any insight would be appreciated.