So much easier for a drummer to drag a guitarist round than vice versa. Whole lot less obvious to an audience as well. Other options: Guitar breaks almost always end on a big sustained bendy something that ain't all that rhythmically dogmatic. Drummer does a roll in to warn the guitarist to watch where the tempo is about to go.
Even if the guitarist is clicked up (ain't gonna happen. almost never a need for it.) there is still the issue of synchronizing his click with the one the drummer is using.
Yes but.
Depends on your ear sensitivity. Some listeners notice a player getting dragged back.
Also re your last paragraph, in the example given above guitarist is a quaver ahead so their new one is between clicks not on. That's a tasty challenge for staying in time oncethey are joined by the rest of the ensemble. It's also a recipe for disaster if there are preprogrammed backing tracks and/or visual effects to the click...
But even in a scenario where there is no click, no unaccompanied sections of a song etc, the band still sounds better if they are all taking responsibility for the groove and not being wrangled by the drums when they wander off.