What's the point of FILL_AND_STROKE?

afaik: FILL fills your circle, while FILL_AND_STROKE also draws the border. If you increase the size of the stroke, it should result in different circles sizes (only visual!)

Think about this: you draw a circle by hand with a small sized pencil. The radius is what you wanted. If you now take a big brush and draw the circle again, your radius is much bigger... (i hope its understandable O.o )

I guess the FILL_AND_STROKE is particularly useful, if one would animate between STROKE and FILL, while wanted to retain the size of the drawn object.

I'm giving an example with the first one below is animated between FILL_AND_STROKE to STROKE, while the second is on just FILL to STROKE. You could easily see the size shrink.

Hence FILL_AND_STROKE is pretty handy here to make size as consistent as possible with others that have STROKE, without have to manually adjust the size of the drawn object (which is complicated)

Yes it's a bit silly. The only use for it is if you want to change between a stroke only and a filled circle then you can use FILL_AND_STROKE to keep the size of the circle the same.

If you went from STROKE to FILL you would lose the width of the stroke when you drew the circle again.