NixOS learning curve maybe is not so hard. You can start with default configurations and installed Calamares what is as simple as on other distros. Than look for options and try.
Otherwise, Flatpaks are reproducible (build with flatpak-builder as on Flathub).
I'm sick of all the attempts to whitewash the recent Red Hat move. This makes things only worse. Fedora will not be affected, Alma has a bright future, CentOS is open to all, "rebuilders", clones...
Major: Debian, Gentoo, NixOS, Arch and also FreeBSD (not GNU/Linux but still).
Other and esoteric: Void, Alpine, Solus, CRUX, Slackware, Mageia/OpenMandriva,
Corporate sponsored: Fedora, openSUSE
Painting a target for fascists or to whom?
I switch between apps from overview or by typing in search, or by sliding between workspaces. It is more convenient to me than classic desktops with a taskbar and minimized windows.
Always has been.
But to be fair, openSUSE was my first linux distro after Windows and YaST had been helpful to me before I learned how to use console commands. And then I switched to another distro.
Flatpak was started by RH employee but has been developed with significant community effort.
Flatpak uses ostree, which was originally created in GNOME for GNOME OS. And GNOME has contributors not only from RH but form Endless, Collabora, Purism and others.
Flatpak can work with OCI remotes, this is what RH more interested in. And Flathub uses only ostree. OCI remotes are used in Fedora Flatpaks repacked from fedora packages with the runtime based on fedora. But who use it anyway.
Flathub itself is independent community effort. It uses org.freedesktop.Platform based runtimes which are not based on any distro.
XDG Portals are shaped by Flathub maintainers and applications developers where RH also doesn't play significant role.
I use flatpaks mostly. Flatpak dependencies (runtimes) are stored separately from the host system so and don't bloat my system with unwanted libraries and binaries. App data and configs are stored separately and better organized. Everything runs in sanboxes. I use overrides extensively. All these are very convenient for me.
And ChromeOS is even more popular.
What you see when you upload files is not a FM but an open file dialog. Yeah, it sucks. Maybe it's worth to play with xdg-desktop-portal and alternative fronteds: e.g. xdg-desktop-portal-kde. But I don't know if it's better.
First of all, I think an idea of package management separated from a system environment is generally good for desktop usage. And don't like and the idea to place all existing application software in distro repositories. But implementations are far from ideal. So I list those bellow from worse to better.
AppImage. It highly relies on the environment doesn't have native sandboxing, and promotes bad practices like building apps with old libraries.
Snap. Snap is mostly fine but relies only on AppArmor for confinement, has performance issues for a long time without significant progress. It promotes a proprietary app store. Relies on Ubuntu infrastructure. Good: snap store support signed packages and more friendly to developers.
Flatpak. App start time is near to native. It has stronger sanboxing but with many holes for compatibility. It true distro-independent as well as popular runtimes are also distro-independent. Bad: Flathub doesn't support signed applications. Sandboxing and permissions rely on hacks and tricks which are far from good design. Development is slow but it is true for the mentioned above as well.
With that, I am more open to new alternatives, especially if started from a system point of view rather than from a position of distro-independent package managers like Google did with Android. For example, sandboxing can rely on users separation and work on various operating systems not only with Linux kernel.
There is no god on Wayland.