+1 for HereWeGo. It's really good for navigation (for my personal experience it's better than MagicEarth) and it does collect minimum data.
Didn't know about Mapy, why do you choose it?
You can watch YouTube video in mpv (just launch mpv with the link the video you want to watch) and, since mpv support HDR, you can watch HDR YouTube video on plasma 6.
See this for how to set up mpv to play HDR video.
Arch btw: it is much stable that many Linux users think, there are a ton of guide to do/repair things thanks to Arch Wiki, and, last but not least, it has the AUR repository in which you can find basically all software you will ever need; the only malus the AUR repository has is that you have to compile every software you install with it (even if sometimes they are precompiled).
P.S. if you want a "ready-to-go" arch distro, install EndevourOs and set the btrfs file system with timeshift. Here's a guide.
I can confirm that Mullvad VPN client works quite well on Linux.