When I download in Firefox, I always specify the destination.
Otherwise, I do *NOT* know where it puts it.
GUI can be just as obtuse as CUI.
I also always have all my browsers set to ASK where to download since I put
different things in different places and there is a place for everything
before I download it.
I think I had to implement a hack in Edge to get it to ask ... let me look
.... nope ... the hack is just to let me put everything in a place of my
choosing - but it's only one place.
So, other than Edge, all the other browsers have a switch to just ASK where
you want to put each file (which is exactly what I want since each file has
a separate place it belongs).