Why did Superman's legacy numbering move to Adventures of Superman in 1986?

After John Byrne's "man of steel" reboot series in 1986, the "Superman" numbering transferred over to the new "Adventures of Superman" monthly title, and a new Superman #1 started.

I never understood the reason for this, why not keep the Superman issue numbering and start a new Adventures of Superman #1?

Anyone know?

I think it was a Byrne demand, although I can't find a reference now so maybe I just imagined it.

They wanted to give John Byrne the glory of a new SUPERMAN No. 1--while still keeping the old numbering. Arguably this was the first issue of SUPERMAN numbered as 1.

They've done the same for other big name creators.