What would be the best device to put any of these ones over the desk? And old phone? Maybe an esp32?

"Number field" felt like the best spacial representation of a numeric clock (would need to be 24h to be perfect but that's a small tweak)

There are plenty of them in a more linear style, but the 12 columns design really works well IMHO. It's really easy to roughly guess the time at a glance.

https://clocks.dev/clock/number-field

I've seen and used some variations of these in my Pebble watch.

They're cool for one day or two. But, in the end, I will always go back to some boring but more information-dense one (with battery charge, weather, heart rate, steps, etc).