both in a GUI? no clue. conky is my guess too for a desktop prescence.
but realtime as in CLI there isbandwidth
in the repo...
I usehtop
for cpu usage...
but bandwidth and cpu both at the same time on a single CLI app? no clue. for as many hardware monitors/system packages there are (solus repo/flat/git) someone has had to invent these two in a single reading...
also, budgie's own System Monitor shows close to what you need: