The RP2040 can be convinced to bit-bang Ethernet (yes even 100Mb/s) with only a transceiver. Part of the trick is to modify the common PHY + MagJack breakout boards to let the RP2040 generate the clock signal so that the signals are in sync and you don't have to oversample the RMII.
Just 10Mb/s can be done even dirtier. I'm still waiting for someone to combine an RP2040 with DVI/HDMI video output and Ethernet into a "modern" glass terminal (just telnet, SSH is probably asking too much).
VGA is much easier to produce, and the RP2040 can do 1280x1024@60 no problem. The official examples use several clock cycles per pixel (2 IIRC, but it might be even more), but you don't have to.
I made half a terminal with that output, aiming for something that ran the original VT100 ROM. I never finished the emulator part, but I did write video output (including scan line emulation) for VT100 memory -> VGA. Adding SSH once the rest works should be perfectly possible. (Not bit banging ethernet at the same time, but using some external chip.)
I should probably put that online somewhere. Or finish it and then put it online.
But of course it has been done: https://github.com/Wren6991/picodvi
(OK, it's DVI rather than HDMI - at low resolutions HDMI isn't more difficult, just more legally contentious.)
Just 10Mb/s can be done even dirtier. I'm still waiting for someone to combine an RP2040 with DVI/HDMI video output and Ethernet into a "modern" glass terminal (just telnet, SSH is probably asking too much).