I would say go for the macbook, its honestly better for any kind of professional work
I dunno if 16 gigs of ram would be enough tho, depending on how heavy your workload is
either is good enough, it's up to whether you prefer mac or windows
I have a XPS 13 and it's solid, I can recommend.
However, you should look into the programs you want to use. There are some that can only be used on MacOS and vice versa.
If you are looking for Windows machine that can do it all at your budget, I would also look into Razer laptops. You'll get gaming + video editing + music production etc in one machine.
If you're planning on using Logic Pro X, mac is the only way. If you're planning on using ProTools, Ableton Live, Cubase, Reaper, FL Studio, or pretty much anything else, you can go for a windows laptop. Though you can use these on a mac too.
If you ask me, I'd go for mac (even though I really dislike Apple)
The laptop itself does not matter lmfao. Its not like the more expensive laptop will magically make FL studio sound better. Get a mediocre laptop. Invest the rest into a good amp, speakers, headphones etc. and maybe a midi board.
Bump need sum more opinions