Supervirulent plagues are also kind of tricky in this regard. For one, they'll leave all technology intact. Not just bits and pieces but just about everything. There'll be millions of homes with televisions, first aid kits, new papers, manuals and so on.

Secondly... the most skilled people will also be the most protected. For one the goverments will go out of their way to protect them, but also that many of these people work in locations reasonably easy to isolate. The plague will hit regular people hard, but not military personell, not powerplant engineers, not medical personell (whom will be best protected of them all)

And thirdly... it's effectivness will drop the more and faster it kills. The only way for 99% of the population to effectively get hit by anything if the incubation period is so long that 99% of the population is affected prior to the massive die off. It just isn't that feasible.

Finally... even with 99% dying off... there's still 70 million people left alive. Recovery population wise will take forever, technology wise there's enough people left to run close to anything remaining.

How about just running a big mystery instead? Noone knows why the modern world just vanished. There's bits and pieces of it hidden in the forests all over the world, but no trace of the people that built it. Even the space colonies don't know... they just lost radio contact one day a couple of generations ago.
A big advantage is that there was noone around to teach people how to read or work the machines, which means that just about every piece of technology is a irrecogniceable mystery. There's no instruction on how to use them or care for them.