Extending on that era’s TV programming (born in the late 70s), even if it wasn’t “your show”, there was only one screen in play. Secondary devices came much later.
You would be surprised at how easily they can be thwarted by simple technical maneuvers.
YMMV, but ime a lot of people have this bogeyman caricature of who the feds really are. The reality is that these are government agencies that pay significantly below market rate for really intense, highly demanding work shrouded with multiple layers of government grade red tape.
I think it's not a bad idea to overestimate the power of the government to track you; the common wisdom on the internet to make this assumption is probably a good thing so people are motivated to be as safe as possible.
On the other hand, it seems like the Tor users who get caught make clear, glaring mistakes in their opsec. And I always remember how long it took to catch the Unabomber, and how they apparently only managed to catch him because of his brother.
I think the biggest trick is to move around, so it isn't as simple as getting a single address. Like with Bin Laden, a lot of the work was figuring out where he was. And Ross Ulbricht, maybe he wouldn't have been caught so easily if he changed hosters occasionally and the VPN had listed 100 internet cafes in different cities as connecting IP addresses instead of just 1. Certainly that's the way Tor works, always hopping around routers. It's maybe a bit pointless though, once they get your legal name it's pretty much a matter of time.
It entirely depends on how motivated and how much resources they're willing to dedicate to finding you. They're probably not going to go to great lengths to catch a single copyright violation, so simple precautions may be good enough.
If you're a legit threat to national security, then yeah, they're probably going to find you no matter what you do.
