Privacy is not binary. There are degrees of privacy that can be achieved. Where you would like to be is totally based on your personal situation. If you are a beginner, understand that privacy is a journey.

Regarding which OSes you could use for your computer if Linux is not an option:

Windows in my experience is the worst offender when it comes to telemetry. It is so ingrained in the OS that you'll never be certain there isn't any telemetry regardless of the measures you take. MacOS on the other hand can be configured in such of way that Apple will have very little if any telemetry on you. It also has good permission controls which would cover things like screen capture and logging of keystrokes which you mentioned above. You could do the following:

• Purchase a Macbook
• Opt out of using an Apple Account (as of today it's optional)
• Opt out of using iCloud
• Opt out of any telemetry
• Turn on built-in firewall
• Turn on disk encryption
• Install Lulu or Little Snitch to block any Apple telemetry

This alone will probably put you in a better position than 99% of people (not an actual statistic).

true all the way down to the silicon really. Unless you are prepared to do you own lithography you are on an untrusted platform.

You'll be a lot less private, but it's not black and white.

for mobile a low effort approach is to simply buy a dumbphone and a faraday bag and you're good to go.

Linux is not like a custom ROM, it's just an OS like any other (but many distros do respect your privacy). But yeah, custom Roms are the only way to have privacy on phones other than just using dumb phones. Support open source projects and manufacturers that make devices that use open source software!

This is a highly loaded question.

You are making a number of very poor assumptions based on a number of ridiculous misconceptions.

The average, everyday, human adult is fully capable of understanding their own personal "threat landscape". How they deal with that will vary.

For most; if not all, average consumers; their concerns are still very limited. They're not so much concerned with the provenance, the history, of companies...they just want to duck for the oncoming threats in their landscape. These metaphorical tree branches are what they're ducking under. They have no logical need to fear the entire tree.

Personally, I choose not to live like Stallman, nor do I have fears of big state repercussions like Snowden does. Neither does your average consumer. Functionality is the top priority. Functionality on-par with the CSSC (Closed-Source Software, Corporate) competitor is critical. If the FLOSS (Free/Libre Open Source Software) version can do exactly what people typically want and expect it to do AND cost less monetarily AND can impact their privacy way less than using the CSSC competitor would, then it will be adopted by many and loved by all who use it.

This isn't to say that privacy does not matter.

It simply means that privacy is a spectrum; and everyone has varying privacy wants and needs. For some reason, a large potion of the "tech-savvy" people in the FLOSS community feel the need to measure their superiority in "How private their systems are." The average user does not give a damn about that dick measuring contest; and really would rather not be bothered. They just want the amount of privacy that is right for them, and their specific situation.

It is best to put your ego aside when discussing privacy, or helping someone else to discover and improve their own privacy.

Mac is less intrusive than Windows. Windows 10 is a whole lot less intrusive than Windows 11. You can lock Windows 10 down even more if you use Shut Up 10. It's an amazing piece of freeware. Just be aware that Windows will reset a lot of your options after major updates.

Duck Duck Go is more secure than any other search engine and browser. Firefox is next in the list if you're not on a Mac. Get uBlock Origin and NextDNS.io.

Don't give your real information to companies when possible. Don't browse the web logged into Google, Facebook, Reddit, TikTok, etc.

There are user friendly options if you're willing to use them. There's /e/ foundation's Murena phone that you can buy. It's based on LineageOS for microG with a custom launcher much like iOS. It works out of the box, no tinkering. There's also GrapheneOS that has a web interface for installation. It is only for Google Pixel phones and takes a different approach to privacy than LineageOS for microG. They both work in protecting your privacy. As far as computer OSes, there are many "easy to use" options for the novice - PopOS & Linux Mint are the best two that come to mind.