Okay, but is there any road outside of highways where we ban cyclists? We can’t even keep them off the sidewalks, even when it’s those nearly vagrants on their e-bikes.
It's a very good question, and it comes back to banning vehicles altogether on King Street, save for those excepted. (Local delivery, residents with permit, etc)
Where your claim for "room for cycle paths" could come from for King is if *vehicle traffic* was only one way one lane in alternating directions each major block. This would allow a bi-directional cycling lane the other side of the road, but of course, it would also require crossing the street at every major intersection.
There would be the option of of a single cycle lane opposing direction the side vehicular traffic is banned, and bikes sharing the vehicular lane remaining the other side and direction.
Frankly though, as an avid cyclist who hasn't owned a vehicle or had a licence to drive in this jurisdiction for decades (and only miss it for highway driving to relieve others long-distance)(I've had licences abroad that have now expired), with the 'cycle express lanes' on Adelaide and Richmond, albeit poorly policed, King Street isn't needed for cyclists. You want to get to a business mid-block on King? Cycle up/down the nearest intersecting street, and walk on the sidewalk with your bike the rest of the way.
King is intended to be a *transit mall*, and what space is left should be for pedestrians. The only access mounted cyclists should expect is where vehicles are also allowed. That being said, it's my belief that pedestrian spaces should also be controlled such that walking willy-nilly into streetcar traffic is prevented, or we'll end-up with the same 5 kph speed limit imposed on trams in the core section of Bourke Street Mall in Melbourne.
Bourke Street Mall is a *destination* for various routes, not a major transit artery like Toronto's King Street.
Edit: Note from the video @ 1:00 minute the signs, one of them banning bicycles through that controlled core section.
The "Give Way to Pedestrians" in that section deems it a *Pedestrian Mall w/ Trams*, not a *Transit Mall w/ Pedestrians* something that has caused endless grief for operation of the trams in that section, and the imposed walking speed for trams, flashing of lights, and clanging of bells continuously through that section.
Also note that the continuing section beyond the pedestrian mall core that does allow vehicular traffic and cycling lanes (width of street far greater than King St) bans vehicles from running along the tram tracks, only allows crossing them.