Bound methods simply has the potential to be a tiny bit more readable:

`thing.doWork(arg)`

`doWork(thing, arg)`

`doThingWork(thing, arg)`

The first example is marginally more readable IMO. The second one sucks from a human perspective because we don't immediately know (unlike the IDE) that the function signature only accepts Things. The last one addresses this but is even longer, and we still have to mentally unpack the args.

IMO there is not much profound about OOP, but it can lead to slightly more readable code if used appropriately.