My alternate reality "one of these days" projects is to have a RISC-V RV32E core on a small FPGA (or even emulated by a different SOC) that sits on a 40- or 64-pin DIP carrier board, ready to be plugged into a breadboard. You could create a Ben Eater-style small computer around this, with RAM, a UART, maybe something like the VERA board from the Commander X16...

It would probably need a decent memory controller, since it wouldn't be able to dedicate 32 pins for a data bus, loads and stores would need to be done wither 8 or 16 bits at a time, depending on how many pins you want to use for that..