Why I have multiple PFS Volume Macintosh HD - Data and how to deal with it

Essential system files are all in "Macintosh HD". User files are in Macintosh HD - Data".

As you appear to have two of those, you can delete either.
One of them, presumably the larger one, is likely to contain files you had before the repair. You can use Disk Utility to mount & inspect its contents.
If there's nothing on there you need, then you can remove the partition.

macOS's container structure will then allow the other volume to dynamically use [almost] the entire container for your solo Macintosh HD - Data volume. Volumes within a container don't really have a size, their boundaries are flexible.