Bands using click and backing tracks is pretty common for most touring bands at this point. I’ve found it to be much more rare to find touring bands that don’t use those, unless it’s a more simple/energetic hardcore band.
The annoying part of this is more bands are not using cabs live, which pretty much always sounds worse in most venues
Ah, I’d doubt that. I often play as a support musician for touring bands (most recently Marco Mendoza), and hardly any of them use backing tracks. I think it depends heavily on the music genre you’re in. From my job as a user experience specialist, I know that as soon as someone says “everyone does it this way,” closer testing quickly reveals that “everyone” is usually less than 10% of the actual total ;-). Unfortunately, I find every day that one’s own experience and common sense don’t necessarily align with those of the majority of users.
And whether it sounds better plugged directly into the PA or picked up through a cab depends heavily on the venue and the people behind the mixing console. Though, of course, one could cheekily ask whether all bands don’t use IEMs these days anyway. Probably about as many as those who play with backing tracks ;-).
At the end of the day, it really has to sound good for the audience above all else. Good sound on stage is nice, but if I have to choose between good sound on stage and in the audience, I’d rather have the sound in the audience. Because the better the sound there, the better the atmosphere, and the better the gig.