Chromium doesn’t need Chrome to exist either: it’s a separate project and if Google doesn’t want to support it anymore, someone can easily fork it to continue having Chromium-based browsers. That’s the property of open source: anybody can inspect and fork it.
Xorg and Wayland are two protocols every Desktop Environment use and is, from my limited knowledge on it, the thing that tells the DE how to behave and display windows on your screen. Since 1984, the Linux world uses Xorg (now at the 11 edition: X11) but now, there is a massive transition towards a protocol more secure and focused around privacy called Wayland because first, it’s objectively better, and because X11 will soon be deprecated/abandoned. But due to its way of handling things (like for example, windows can’t see each other: they think they’re alone on the PC, preventing some programs from spying on each others but also preventing them to communicate with each other, like to share screen or screenshot. We have portals to solve that now though, so no worries), Wayland struggle to convince everybody and therefore is heavily criticized, mostly because it’s sort of being forced due to the Xorg team letting the project die to develop Wayland, the successor, waiting for every distros and their DE to adopt it.
But despite not directly mentioning those protocols, you’re right by saying “you can just jump ships and unsubscribe from what you dislike” because honestly, nobody’s preventing people from continuing to use Xorg and groups from continuing the development of DE based on Xorg or simply continuing the Xorg project, but if they want to progress and evolve with the rest of the world, they will have to switch to Wayland eventually.