Gnome will die the second Cosmic (Epoch) DE gets remotely close to 1:1 parity. It will be more stable, it'll be more feature complete & support modern features, it'll have a similar level of polish, a similar yet way more flexible design language and the devs will actively work with the Linux ecosystem & so on.
At that point the only people left over for Gnome, are those stuck on x11, and die hard shills/fanboys. Many developers are very much sick of Gnomes shit already and only put up with it because it's popular.
Perhaps or perhaps not. Every new desk top was going to be better than Gnome when introduced. I remember having such high hopes for Elementary back in the day too. It was so elegant and smooth to use.
System76 is no stranger to desktop development nor Rust-lang. Their team is relatively large, skilled, diverse, and highly dedicated, with years of experience in high-level and low-level development, UX/UI design, and even an OS built from scratch (Redox OS), and so on. Unlike elementary OS's Pantheon, which builds upon existing frameworks like GTK & forked Gnome components, Cosmic (Epoch) is entirely written from scratch, toolkits and all. System76's approach is also more comprehensive and ambitious compared to elementary OS. They're developing native Rust applications like the COSMIC app store, terminal, screenshot tool, and text editor. Early performance tests show promising results, even in virtual environments.
The company's financial resources also allow for significant investment in COSMIC's development, supporting a dedicated team and a long-term vision. This contrasts with elementary OS's more gradual, community-driven growth.
Pop_OS! is also an already very popular distribution, and importantly popular amongst newbies. System76 is also a hardware vendor meaning they can tightly integrate Cosmic with their hardware, and in fact do so much more easily than what they've already been doing with Pop_OS!.
Compared to ElementaryOS, System76 is in a much better position.
If any of that happens I'd switch. But I'm very skeptical as I used KDE many years ago and the big plasma release doesn't look much better than it was back then