i've been a big fan of fedora's atomic distros and i decided to make my own but arch based to get the best of both worlds, which is kind of funny now because it looks exactly like silverblue. is it worth it? not sure, but it's been a interesting experience – and it's usable as a daily driver if your specs match.
worth noting that because of the constraints of the setup you can develop something similar on your main machine without any realistic possibility of data loss since you never really touch the bootloader or the filesystem (partitioning and so on).
For example, it is quite annoying to have a sane font setup due to Arch shipping vanilla. Fontconfig sucks, it has bad documentation and Arch Wiki examples go only so far. Among the entire distro universe only Fedora has sane configs. So an immutable Arch goes against immutability.
Moreover OSTree requires a server to receive updates regularly, are you going to put the effort to building the OSTree multiple times a day? Why should we trust a single person?