Raspberry PI OS 32bit is compiled for ARMv6 to support the orginal Raspberry pi. I wonder what impact on benchmarks there would be compiling for ARMv7 hence only supporting Raspberry pi 2 and later?

I've been operating 64-bit kernels and user-space for at least a couple of years for embedded and network and server usage and not experienced anything to even remind me it's 64-bit rather than 32-bit.

I've used both the original Raspbian 64-bit builds and plain Debian 64-bit with the few required RaspberryPi specific tools added in. Kernels are all self-built (cross-compiled) keeping up with mainline Linux.

Since packages are derived from Debian (which supports arm 64), I assume pretty much all packages you can install from the Raspbian repos for 32 bit will still be available.

Which begs the question of what is even the point of having their own distro anymore. Why not just push a bit more to land their changes upstream in linux, and make debian the default noobs install, while providing the option to do all the other OS's as well.

I've said this before, that instead of focusing on building a custom distro everyone would benefit if they instead focused on just enabling all the other distro's and OS's. Pretty much everything, including windows runs on the darn thing, its the closest piece of HW in the arm ecosystem (other than the server class machines) to a random PC motherboard when it comes to just about working with any given OS.

There's sense in trying to keep their diff from upstream fairly minimal, but I can see value in having some differentiation - if nothing else, the RPi foundation probably wants to ship Pi-branded images (default background, application menu icon, that kind of thing). Also, there might be issues around nonfree requirements, although I'm having a surprisingly hard time finding information about that; I know booting the Pi requires a nonfree firmware blob, but I'm not sure whether there are any ex. wifi driver issues.

That said, yes one would very much hope that everyone can work together to make the diff between Debian and its downstreams as small as possible given the constraints that each party operates under.

I see. That sounds very promising!