Well, as a proof of concept, I'm writing this answer on my trusty Dell Inspiron 15R N5110, running Debian 10 Buster amd64!
Everything works fine, including 3D graphics support, wifi, keys for brightness, sound, wifi switch etc.
On Debian, after installing the OS you need to add
non-free repos in
/etc/apt/sources.list. Then you can plug an ethernet cable to the ethernet port (it's a Realtek which works out of the box) and install these packages:
apt install firmware-brcm80211 firmware-amd-graphics
My laptop has Broadcom wifi and ATI Radeon HD 5400 graphics, so the above line is needed to add the firmware for these devices. There are variants of the laptop though I think, having other devices installed, in that case you'll need the respective firmwares.
apt search firmware-.* will be helpful on such occasion.
Perhaps Debian derivatives like Ubuntu or Mint automate this process so you won't need to add any firmware by hand. But since they also add lots of bells and whistles, some of them unnecessary, they cannot be as fast and snappy as Debian.