I agree that hacking is a little adventure in itself sometimes, but shouldn't the GM account for that during adventure preparation? if the other players just sit by and wait, I guess that's more of a GM's fault.
I don't know how 5e works though...
It's a bit difficult, though, if the team decides they want the hacker to get control of everything before they go in, or if he's doing that while they're getting in - either he does things the long way, which has to be done pre-run anyways, or everything he's doing is at the timescale of a Combat Turn, with the Hacker probably being in VR acting 3 times a Combat Turn, effectively getting an entire action phase every second. When the team is in something that's on the same sort of timescale, it's easier to jump around. Of course, with the extended tests, you can always have the player make any declarations he needs to, tell him the threshold if he doesn't already know it (which he should), and have him roll in the background while other stuff is going on; or you can give him breaks to plan what he wants to do.
SR5 does make things faster, puts all hacking on a running clock, and encourages you to get close (ideally "plug right in" close) to a point of access. It also does terrible things to technomancers, but still.