Really jumped in the deep end with your research, huh? :)
I guess a good place to start would be deciding what actually bothers you. Megacorp sucks because of [shitty capitalism, shady labor practices, locking down devices, privacy, insert other complaint]. Weigh those against the benefits you get.
My biggest concern is generally privacy and monetization of my data, but I still use an iPhone because my family wouldn’t get off my case about ease of sharing photos, videos. So I only have the iPhone. Don’t buy anything else from them. I turn off as much tracking and data collection as possible. I only have two outward-facing files in iCloud — my encrypted password keeper so that I can access it both from phones and mobile, and an encrypted file vault that can only be opened if you first get into the password keeper.
FWIW on the FOSS side, I still use Linux. I used to use GrapheneOS on a Pixel 5a that worked otherwise well.
Idk how to edit my comment on this app, but my password keeper (KeePass) and vault (Cryptomator) are also FOSS fwiw.