They clearly lead in Linux development, especially with third-party support only available through them. Trying to avoid them isn't feasible. You must rely on their code and approaches to work with Linux. Ubuntu ranks second in size and they sometimes push boundaries (like upstart versus systemd), though success is inconsistent.
You're looking for a lightweight RHEL setup? Yes, that's achievable. It's feasible to install Linux distributions without Linux itself and avoid GNU components. You don't need systemd, PulseAudio, RPM, or even a network manager. In fact, you can strip the network manager from inside RHEL if you prefer. While it simplifies some tasks, Red Hat tends to include GUI environments in their server images for consistency across products. You won't have to master network manager, DHCP, or connection tools all at once. It might be challenging as a sys admin to adapt to changing tooling, but eventually you'll assess whether the trade-offs are worthwhile.
You often encounter situations where vendor rules align with policy, yet you're left with limited options. Many are trapped in middle management without clear paths forward. This isn't a conspiracy but a deliberate design by RHEL. They excel at converting open-source projects into closed ones. While Alpine and Gentoo are fine, they lead to more complex custom setups that are harder to maintain. FreeBSD is an exception but isn't Linux, which brings its own drawbacks. As for the current state of Linux, most of it feels like a struggle—especially compared to Windows, though it's better than some alternatives.