Fedora 37's Silverblue & Kinoite Look To Default To Read-Only /sysroot
OSTree already supports remounting /sysroot as read-only and this Fedora feature change is about enabling that by default beginning with Fedora 37 for the Silverblue/Kinoite spins.
Users are not expected to be manually messing around with /sysroot data but instead adjusting the system via rpm-ostree and the likes of GNOME Software and Plasma Discover for managing your operating system state. Thus in going read-only by default they hope users won't accidentally mess up their systems.
This read-only change is only in regards to /sysroot with / itself not being affected nor locations like /etc and /var.
For those using Silverblue/Kinoite, you can learn more about this planned change for F37 via the Fedora Wiki.