I started with an RPi 1b to read out my weatherstation (WH1080 clone) and post it online with weewx. Then a Bananapi R1 entered to replace my intel system as firewall/core router (savings on power usage, a lot). The RP 1 got replaced by a RPi 2, and tne 1 moved to the smartmeeter for readout. The main server (huge AMD tower) got replaced by a RPi 3 (again, power savings), Bpi R2 replaced the R1 when bananian development stopped. RPi 3 died on me (sd slot failed) and I got a replacement. As the 1st RPi3 was dead anyway, I tried to repair it (only use of the solderings at the side proved to be to keep the slot in place) and used it to replace the Bpi R2 as support got problematic.
The main server got upgraded to a RPi 4 8GB, with the RPi3 replacing the RPi2 that was handeling my weatherstation. I got an rflink, so I added domoticz and that now powers my kaku (dutch power switching system) in a mixed old/new setup. The RPi3 that was my main router (internet router via fiber) got replaced hh an RPi4 witn 4 GB mem, as the 2 GB mem version wasn't available. (Not a bad move, with the on-board non-usb 1GB interface and a tad over 2 GB mem use)
The freed RPi3 is now for the smartmeter, so all RPi are 64 bit. (All running aarm64 Debian) Both Bpi's and RPi 1 and 2 are collecting dust, as I haven't found a use for them... yet. Looking for projects to use them. As media server they're to light. (Although, Bpi R2 could be useful for that)
My main desktop on Debian, left QHD screen, right full HD. (needed the old QHD for remote sorkspace) Debian Trixie with XFCE4, DarcCold style and Adwaita Icons. Didn't do much tweaking, yet. Switched to XFCE4 3-4 years ago after running CTWM since '96. (Still use that desktop for my vnc environment on my main RPi)
I'm guessing right of the right shift.