• Not everyone that uses Linux is against proprietary software or only uses FOSS.
• There are people that just heard of Linux, are just trying it out, or have an issue, and already use Reddit, or is what the search engine points them to go for help, or to ask questions.
• Reddit has a lot more reach for the common people than any other platform at the moment, there are still people that prefer to ask on Reddit, than go to a specific forum or another platform to ask (If I remember right, it still happens with some apps like Jellyfin that moved out of Reddit, but people still ask there)

These are just a few of the reasons that come to my mind.

MSI Sword 15 here, with Intel + Nvidia, In my personal experience is runs almost without issues using Manjaro as a Distro (have not tried other distros on this specific machine).

Your experience could be different depending on your specific laptop model and how recent it is.

Keyboard lighting and fan on/off works without issues, the only ‘Fn’ key that does not work apart from the one for MSI windows software is the one to block the trackpad (and I just configured another keyboard shortcut for it).

Using Wayland, I can not use an external monitor connected to the HDMI port on the Nvidia card (No idea if it is fixable now, haven’t looked on it recently), but with Xorg I can run an external monitor in the HDMI port and extra ones with a dongle on the USB-C (so far tried with 3 without issues)

Friendly distros recommended these days as far as I know are Mint and Zorin if looking for something Ubuntu or Debian Based, Apart from that there is Fedora or Arch based distros but may need a bit more knowledge and getting used to.