Canon EF 11-24mm f4L vs Canon EF 16-35 f2.8 L III

[GMCPhotographics]

If the range is suitable, the 11-24 is a perfectly fine lens. I found it too heavy with the 1DX but fine with 5D or 6D (or Sony mirrorless, where it actually works with the stabilization very nicely).
In the less extreme range it has better distortion control than all the other EF lenses (including the primes) and it is more than sharp enough everywhere with some border CAs that are easy to correct.

Right....by distortion control...I'm assuming you mean that straight lines stay more straight....but circles get distorted into weird egg shapes? With ultra wide lenses, there is either fisheye or rectilinear corrected. There are no other types of wide lenses. The amount of rectilinear correction is down to the lens engineer and intended lens usage. With a fish eye, circles stay round but a fully corrected rectilinear lens...the straight stay straight. but in both cases the opposite happens to the straights or circles. Neither is correct.
So a lens engineer (or lens program) dials in the correction based on what the intended usage is for. Something like a 14L, TSe 17L or 11-24L is likely to want to shoot architecture more than people. So it's corrected for straight lines (but makes a mess of faces / circles etc). Something like a general ultra wide (16-35 f4LIS is a good example) is corrected for general use, allowing post prod to perfectly straighten lines or enhance circles. It walks a median path through them both.
So please don't think that a 11-24L is a better corrected lens...it isn't...it's just better for straight lines, which may not be what you need in every situation. I have a TSe 17L, a 16-35IIL and a 8-15L fisheye for this reason...I need the right tool for the right situation.