Although RaspberryPI foundation are working on a 64 bit (RaspberryPI OS) it is very much beta, and the only thing that seems to have spurred them to it, is the release of the 8gb version of the RaspberryPI4. However Archlinux ARM is now exclusively 64 bit and my opinion very much ready to go (and I’m sure they’ll take advantage of RaspberryPI foundations work). Recently I released a version of PiCrate that is compatible with both 32 bit and 64 bit distros.