That would give you a circumference of around 628m. That sounds like a lot, but if you could build it in 80m segments by bolting each segment to the outside of SpaceX Starship (which is 120m tall) that would take 8 launches to get the ring in orbit. Plus some more launches for the hub and spokes and panels and everything else of course. Still, 15-20 launches is not outside of the realm of the feasible. If there were the political will (or personal fortune) to build this it could be done.
Split the initial station into two stations with a large number of cables connecting them securely. Now on your calculator, put in a 70m radius and a gravity of only 0.3g. All green dots.
But how do you get between the halves?" you ask? I think there's a simple answer to that: have cables complete the circle. A small car riding those cables can carry you around the radius. Then over time, you add more cells until the circle is complete!
The zipline would be trickier to make work, then. Probably you have a gadget that walks up the tether, and then you flip around and it walks down to the other end.
Basically, we would need to make something hundreds of meters in diameter to have any hope of a comfortable living situation. This is a huge amount of mass to get into space, which is notoriously expensive, but getting cheaper every year. Maybe one day we'll hit an inflection point where this is reasonable.