Google tracks you, yes. But Google also takes good measures to ensure that they are the only ones that can track you (and the Google Play apps of course). You may be obsessed with Google and they tracking you, but that's ok. What I think is wrong is saying that your solution is more private or secure. Privacy relies on security, and I believe your solution is not more secure than a flagship stock Google phone (let's not engage in the Android heterogeneity and lack of updates). I'm sure that any dedicated actor who wants to compromise F-Droid or any of the apps in there could do it without major effort, rendering your privacy useless as you got completely owned. The same for your custom ROMs.

What you achieve with custom ROMs and custom app stores is customization capabilities and nothing more. If you believe you're achieving next-level security or privacy because you don't have Google installed; you're kidding yourself. Yes, you may be leaking (at first glance) less data to advertisers; but you've opened a whole different kind of attacks that could compromise all your data on your phone, not just what Google and the Android platform allow to share.

A perfect example is the "LibreSignal" project you mentioned, what kind of joke was that? The project was abandoned because it didn't get Moxie's blessing? That's a really strong sign of commitment with the cause. I'm sure that LibreSignal has more than zero active users, what do you think about their security/privacy level currently?