My exact choices. I want to love the open source phone options but... Corporations have embraced android and iPhone. I worry about road blocks with things like duo and apps that don't permit install on rooted things etc.
[1] I prefer FreeTube on computers where I have it installed, but one of my family's jank 10-year-old work PCs can't handle it, so I'll typically watch videos in Invidious in LibreWolf on that computer.
[2] I can't recommend Debian for absolutely everyone since it prioritizes stability and predictability over new features and ease of use, but it's great for most of my use cases. I typically recommend Linux Mint for complete beginners.
[3] It handles extremely large music libraries (>100 GB of .mp3 files) without constantly taking forever to reload when I add a single new album.
[4] Firefox is pretty good and FOSS, but LibreWolf comes with better defaults and I'm a lazy fucker.