I'm really not sure as to what the "best advice here would e!
A key issue is that you are shooting full frame. To me, the choices were pretty cut-and dried. canon provides the 16-35 and also the 24-105, both of which to me have been great lenses. I've also had a 24-70, which delivered good quality performance, and so the 24 is a bit wide for full frame.
However, for me the "champ" for an all-purpose walk-around lens has been the 24-105, it's a very nice veratile lens!
As to shooting wildlife, well, I'd tend to take another route, a longer lens. Early on I used the Canon 70-200 lend, a good performer which gave a bit on the length end, although for wildlife type of stuff I stuck 6to longer telephoto lenses. My "workhorse in that regard has been the Canon 100-400 VI although I've heard great things about VII.
As to the Siigma, gosh, I'd say if you are hearing mixed reports about that lens, well if were me I'd stay away.
As to your wish to have something "wider", well, like I said the 24-105 has been for me a very good walk-around lens. When I wanted wide the 16-35 certainly delivered, but still the 24-105 is my go-to lens for the full frame camera!
Anyway, good "luck on your choices! Sure, all these things are "spendy", especially since we are talking about Canon "L" lenses. To me, though, I just defaulted for L as the "best" from what I could see. Well, you makes your choices!