It’s basically a drop in replacement for dnf.
As simple as sudo rpm-ostree install vencord. Then you reboot and it’s there. That’s assuming it’s already in the repos. If not, I’d recommend you look into distrobox. It allows you to install apps from any other distro in Silverblue. You can add them to your menu and have them behave as native apps.
Flatpaks are the preferred option followed by the Fedora toolbox container. Then you can make a distrobox container if what you want can’t be satisfied by the first two. You can also layer packages with rpm-ostree but this should only be as a last resort.
There is a bit of a learning curve with regards to how you should approach package installs, but once you learn it and get comfortable with the container options it’s pretty smooth sailing.
Wanted to try out wayland and fedora was recommended as the best experience for that during those years. Discovered the most polished, stable and smooth Linux experience I’d had to date. Mostly used ubuntu distros and arch before. Never looked back. Upgraded to Silverblue to try out the future of linux. Haven’t changed anything since. Been about 3 years now on Silverblue.
It’s not propaganda. Fedora’s just that good. Been using it since 2019 myself. Never felt the need to distrohop after.