Yes, fully open source. If you don’t trust Mozilla, use a fork like Betterbird.

FR, younger generations don’t have to fix anything / solve any problems on their PC; any problem they’re likely to run into is an abstracted error within Google Docs, within their browser.

Mangadex is the best online reading experience I’ve found. Use a unique random password with the site, they’ve had a plaintext password breach in the past.