I use Android and I work on Android apps because it’s the most open mainstream platform on the market. That doesn’t mean I like it, it just means I dislike it less than the other options.
What I would really like is to be able to run a fully open source OS like Linux on my smartphone. Android uses modified Linux kernel, but it’s not a real Linux. I deeply respect people who try to make Android more open like the folks from LineageOS, but it seems like a pointless battle against a hostile platform. Google doesn’t want Android to be fully open, and it controls this platform so there isn’t much we can do about it.
That said, Android is still the only game in town, but times are changing. I’m pleasantly surprised how fast Pinephone moved from the idea to being a functional device selling worldwide. Using a Linux phone as a daily driver is closer to reality than ever, and I believe it could happen by the end of 2021.