Wayland

Ubuntu 25.10 dropped X11 entirely in favor of Wayland, breaking compatibility with many X11-dependent applications. Additionally, Rust-based replacements for sudo and coreutils introduced critical bugs (e.g., breaking flatpaks), causing system failures despite security benefits.

Electron apps don't integrate well with operating systems because they're essentially web browsers displaying local content. When Electron doesn't support specific OS features, apps using it also won't—for example, Discord lacks screen sharing on Wayland and doesn't support file portals on Flatpak.

Developers must support multiple display protocols—X11 and Wayland—as Linux transitions from X11 to Wayland. Not all distributions have fully adopted Wayland, and XWayland compatibility is inconsistent, causing software to run less smoothly than on X11.

Ubuntu frequently makes core system modifications (e.g., for Mir, Unity, Wayland) that are not contributed upstream, preventing other distributions from adopting Ubuntu innovations and creating maintenance burden.