I'm a bit confused as to why it supports OPFS, but not the much more widely supported regular FileSystem API. As far as I understand, this is also capable of re

I'm a bit confused as to why it supports OPFS, but not the much more widely supported regular FileSystem API. As far as I understand, this is also capable of reading and writing to files directly, and also allows seeking. All the user needs to do is select a file in a file picker first. Is there a required feature that only OPFS provides, other than file locking (which seems like a pretty non-essential feature tbh)?