Flatpak will no longer feature in the default install of Ubuntu's 8 official flavors, with devs agreeing to only support deb and snap software OOTB.
In a surprise move, Ubuntu developers have agreed to stop shipping Flatpak, preinstalled Flatpak apps, and any plugins needed to install Flatpak apps through a GUI software tool in the default package set across all eight of Ubuntu’s official flavors, as of the upcoming Ubuntu 23.04 release.
Wait, how did you view this post via Mastodon? I know both Lemmy and Mastodon use ActivityPub but the UX and urlpatterns are quite different and client-specific. What is the format of the link you used to view this?
I found out in the meantime. You can find communities from Lemmy on Mastodon using the @communityname@server pattern. So @kde@lemmy.kde.social will find this community. On Mastodon it'll appear as a user boosting every post (both top post and comments) and that way you can find individual comments.
It isn't great, the UX is clearly different and not made for each other, but it works and you can favourite or boost individual posts with it.