The EF 24-105L II is a very nice lens....

But for an 80D user, it's a waste of money. Since you are using an APS-C camera, for $500 less you can get very good shots with an even more versatile EF-S 18-135mm IS USM lens. At the wide end, the 24-105mm will be a little sharper in the far corners... but at the telephoto end the 18-135mm has less chromatic aberration. See for yourself:

https://www.the-digital-picture.com/Reviews/Lens-Specifications.aspx?Lens=1045&LensComp=1072

At that website are also full, detailed reviews of both lenses:

https://www.the-digital-picture.com/Reviews/Canon-EF-S-18-135mm-f-3.5-5.6-IS-USM-Lens.aspx
https://www.the-digital-picture.com/Reviews/Canon-EF-24-105mm-f-4L-IS-II-USM-Lens.aspx

There also are other side-by-side comparisons available at that site:

Optical vignetting: https://www.the-digital-picture.com/Reviews/Lens-Vignetting-Test-Results.aspx?FLI=1&API=1&FLIComp=0&APIComp=0&Lens=1045&Camera=963&LensComp=1072 Note that the tests of the 24-105 for vignetting were done with a full frame camera. Using the lens on an APS-C would largely crop away the corner darkness seen in the examples

Flare resistance: https://www.the-digital-picture.com/Reviews/Lens-Flare.aspx?Lens=1045&Camera=963&FLIComp=0&APIComp=0&LensComp=1072&CameraComp=979&FLI=1&API=0

Distortion: https://www.the-digital-picture.com/Reviews/Lens-Distortion.aspx?FLI=1&FLIComp=0&Lens=1045&Camera=963&LensComp=1072

General specifications: https://www.the-digital-picture.com/Reviews/Lens-Specifications.aspx?Lens=1045&LensComp=1072

Note that I specified the 18-135mm "USM" version. It's the same optically as the slightly earlier and less expensive STM version, but Canon claims the "Nano USM" offers 4X faster focusing. That can't hurt in some shooting situations. The USM version of this lens is also the only Canon lens that can optionally be fitted with the PZ-E1 Power Zoom module, which someone shooting video might appreciate. All versions of the 18-135mm have IS, same as the EF 24-105mm lenses. Both the USM and STM versions of the 18-135mm provide faster, quieter, smoother focusing and have an improved optical formula for better images quality than the original "micro motor" 18-135mm, which is still available as the cheapest of the three options.

Yes, the 18-135mm has a variable aperture and it's a stop slower at the telephoto end. It's also not an "L" series lens, without the weather resistance or the L-series price tag. It also won't come with a lens hood... only L-series do. The separately sold EW-73D hood costs $35... or there's a Vello clone of it for $13. Either way, I recommend the hood. The 18-135mm focuses slightly closer and renders slightly higher magnification than the EF 24-105L II. The 18-135mm is also slightly smaller and about 1/3 lighter than the 24-105mm. And, hey, nearly $500 saved would go a long way toward a photo excursion or another piece of gear you need!

Some people will tell you that 24mm isn't wide enough on a crop sensor camera. That actually depends upon what you shoot and what other lenses you have in your kit. I've never owned any of the Canon EF 24-105s (there have been three). I've tried the earlier L version, but wasn't impressed. Instead I shot A LOT with a Canon EF 28-135mm. In fact over the years I've used five of them and I know several other pros who opted for 28-135s instead of 24-105s, too. I used to recommend it over the first 24-105L because the 28-135mm had just as good image quality... better in some cases... and it cost half as much. The 28-135mm was also provided as a kit lens option a lot, so there were many of them on the used market that had seen little use and could be bought even cheaper... the most I ever paid for one was $250. Others I got for under $200.

I wore one of my 28-135s out. Another was a loaner from a friend I finally had to return. Another I gave to a friend. I still have two of them, though one has developed a glitchy aperture. Not L-series, they don't seem as well built, though they are what I would call Canon's "mid grade". However, I also have to note that the original EF 24-105L had some reliability issues. It's internal wiring tended to break, causing aperture, AF and IS failure. Ultimately, that L-series lens wasn't any more or less reliable than the EF 28-135mm. I have no idea how the EF 24-105mm L "II" holds up over time. It's reliability may have been improved. But I also don't know how it compares with the EF-S 18-135mm in this respect. As newer lenses, one would hope they both offer durability improvements over the earlier versions (the EF 28-135mm dates back to the 1990s and the film era... the original 24--105L was a decade younger).

I no longer recommend the EF 28-135mm very often. One reason is that it's now been discontinued a few years and good copies are getting harder to find. Also, for APS-C camera users the EF-S 18-135mm USM (or STM) is an even better choice.

My point here is that 28mm wide served very well on my APS-C cameras. So too would a 24mm wide, because I have wider lenses when I want them (12-24mm and 10-22mm). In fact, sometimes I use 24mm too... a 24-70mm f/2.8L on my APS-C cameras, though that lens is a bigger and significantly heavier (not my first choice for all day shoots or anything involving hiking).

But 18mm wide will serve even better. Likewise, 135mm is even better than 105mm.

Today I recommend that Canon APS-C DSLR shooters seriously consider the EF-S 18-135mm IS USM... it's a good, versatile "walk-around" zoom. One of the best, in fact.