My issues with the post start with the tone. It's not a respectful tone, rather aggressive and always flashes me back to people who write similar blogposts about systemd or something else that is new but not accepted by greybeards yet.
Fonts and theming are an issue, I agree, however, this isn't entirely the fault of the flatpak maintainers but in part the fault of a fragmented and hard-to-compose linux ecosystem when it comes to their configuration.
The IME issue is a problem but I don't think a dynamically linked system would benefit much here. The solution is to make portals between flatpak and the system more extensible and versioned, so that an outside daemon an talk to flatpak apps and potentially flatpak could even try to determine which runtime to use based on what outside portal versions are available.
Fonts and theming are an issue, I agree, however, this isn't entirely the fault of the flatpak maintainers but in part the fault of a fragmented and hard-to-compose linux ecosystem when it comes to their configuration.
The IME issue is a problem but I don't think a dynamically linked system would benefit much here. The solution is to make portals between flatpak and the system more extensible and versioned, so that an outside daemon an talk to flatpak apps and potentially flatpak could even try to determine which runtime to use based on what outside portal versions are available.