Don’t get stuck into https://en.wikipedia.org/wiki/Learned_helplessness or perfectionism! So :

• every step counts
• even if you are not entirely private in anything you do, you can still be more or less exposed
• you are not alone in that struggle, we ALL are, from CEOs to politicians to random folks, we are all threatened and must help each other
• alternatives DO exist (as a personal example, I don’t use Google, WhatsApp, TikTok, etc) and enjoyable
• it’s not just technical but also psychological. If you focus on the technology it can be daunting, if you focus on usage it gets easier, ideally you combine both while insuring you don’t burn out.

You can do it, WE can do it! :D

Edit: Crossed out slightly out of date recommendations, see comments.

Do not confuse privacy with anonymity. Your goal is not to defend against governments or other entities with limitless resourced, but against profit oriented companies. By reducing the amount of data you leak and obfuscating what is left, your data becomes progressively worthless as you improve your setup. This is a good thing, because companies will focus their limited resources on areas with a higher profit margin.

Given your description, I think the network side of IT security is pretty much top notch, firmly in the top 0.1% if not 0.01% of users. However most of the tracking happens at the browser level, so it alone does not protect you that much.

Firefox is a solid base, but it is optimized to not break any websites, rather then providing maximum privacy. You can try to tweak settings manually, but I’d rather recommend you to use LibreWolf on PC and Mull on Android. Both are pre-configure, hardened versions of Firefox, that also have proprietary Mozilla features like “Pocket” and some telemetry removed form the source. A standard install has basically no downsides, 99.9% of sites work normally and privacy is quite good.

Librewolf has ublock origin pre-installed and pre-configured with sane defaults. I’d recommend the following additional addons:

• Decentraleyes: Local CDC cache to reduce third party requests. Improves privacy, performance and doesn’t break anything. No configuration needed.
• Privacy Badger: Prevents some interactive features (disqus comment section, embedded youtube player, etc) from loading until explicitly confirmed with a mouse click. Also prevents some tracking in the background, but that might eb covered by ublock already.
• Cookie AutoDelete + I still don’t care about cookies: This combo silently suppresses all cookie pop-ups, allows them for the session and cleans up afterwards. This is different then disabling all cookies, and does not brake websites then rely on them while providing all privacy benefits.
• Disable WebRTC: WebRTC can leak your IP address, but disabling it breaks eg. real-time video calls. This plugin is a simple toggle, only turn it on when you need to.

If you are willing to do some fine tuning or accept broken sites, consider also:

• noscript: Most privacy leaks happen because of Javascript, but disabling it basically makes the modern web unusable. noscript offers a middle ground to enable/disable javascript on a domain-by-domain basis. Can be annoying at times, but arguably the best way to defend yourself.
• Canvas Blocker: WebGL powers most of the advanced visuals, and can read out a lot of data that is used for fingerprinting. This plugin can randomized requested data to protect you, but it also brakes sites in weird and unexpected ways. It’s powerful, but I rarely use it these days.

And finally consider some obfuscation techniques to throw of the remaining trackers. Right now I only use one, and highly recommend it because of its effectiveness:

• Font Fingerprint Defender: Using javascript, websites can read out the list of installed fonts on your device. Some programs install fonts in the background when opening a document with missing fonts, so this list is highly unique for each user and effective for tracking. The plugin throws is some noise, and causes automatic systems to detect you as a new unique user each time.

All of this throws off the vast majority of trackers, and puts you in the top 0.1% of users. Yes, this also makes you kinda “unique”, because websites may notice the effort you put in to defend yourself. Bad idea if you try to hide from the government, you should be using TOR for that anyway, but great to signal companies that you are not worth the squeeze.

Keep your head up bro. The situation is not as terrible as it may seem, but companies want you to believe that, so that you don’t even try.