The distro that comes to mind is LMDE ( Linux Mint on Debian ). The Mint team adds some polish, a better out-of-the-box experience, and some nice desktop tools ( productivity ). In addition, Mint will keep the desktop environment ( Cinnamon ) up to date which counters probably the biggest issue with Debian which is that the software versions get old.

I use EndeavourOS ( a version of Arch ) because, for me, having up to date packages led to higher productivity and greater stability. When I used Ubuntu, Debian, Fedora, or others, I was adding 3rd-party repos, PPAs, and compiling stuff outside the package manager. This always led to a mess over time.

These days, the choice of distro matters less as these problems can be handled other ways. Flatpak allows you to install newer GUI apps ( either newer versions or stuff missing from your repos ). This does not work for command-line stuff or the desktop itself. So, Flatpak compliments LMDE which keeps the desktop up-to-date.

A problem I had with distros like Debian and RHEL was that the dev tools get too out of date. These days, that is easily countered by something like Distrobox. Sandboxing the dev environment has other advantages and, if you muck it up it does not impact your system overall. Multiple dev environments can be handy too as the toolchains favoured by different languages can conflict. If you are not familiar with Distrobox, it uses containers ( like Docker ) but it feels like a much better integrated extension of the host system.

If you use Distrobox, you really do not have to use Flatpak if you do not want to. You can essentially layer on the package selection of any other distro on top of your base system.

I have considered this setup myself, Debian as a base with Distrobox on top to access the Arch packages repos and the AUR. LMDE would make sense for me for the same reasons I have to you. Probably the only reason I have not pulled the trigger yet is that, around the time I had this idea, VanillaOS announced their switch to Debian. Vanilla looks like they had much the same idea but are building it into the core concept of the distro. It has not really stabilized yet though.