It really depends on the intersection. There are plenty of junction which may have a turn which is disallowed and must be manually restricted. In that case the "all turns dis/enabled" won't appear at all. For example, this segment is a ramp
and you don't want to enable a left turn off the ramp across the center divider to go the other way. If you select the junction, you'll notice you can either disable or enable all turns, and that "all turns dis/enabled" doesn't appear because neither is true. If you were to Enable all turns at this junction, you'd end up with Waze giving incorrect, illegal and dangerous turn instructions from this ramp.
So, depending on the exact junction and the nature of allowed turns, you need to make sure it is all set properly, so just ignore the "all turns dis/enabled" and set the turns properly.
The use of QW is only advised 1) on junctions where all turns from any segment to another is allowed and 2) as a shortcut: getting all turns enabled then disabling the one illegal turn is faster than manually setting turn restrictions on each segment individually.