I didn’t mean to baffle anyone. Let me explain. I went to Alaska hoping to shoot landscapes and wildlife. The landscapes I found were beautiful but beautiful with a high degree of redundancy. I now refer to my very expensive—I rented an RV and spent 6 weeks in the state—trip as “the mountains and clouds tour.” As for the wildlife, that involves paying for guided tours. I went there with the notion that bears and moose outnumbered people. They don’t. I never saw a bear or moose. I’ve talked with friends who loved Alaska. Me, not so much.

Nikon makes a 24-120mm "FX" (full frame capable). Canon doesn't.

And... Canon doesn't make an "EF" (full frame capable) 28-200mm.

Canon DOES make an EF 28-300mm f/3.5-5.6L IS USM... That's a fine, high performance L-series lens, but rather pricey, big and heavy: $2449, 3.67 lb., 77mm filters, and nearly twice the length of the 18-135s. It comes with a tripod mounting collar, too (removable).

Compare to the EF-S 18-135mm f/3.5-5.6 IS (three versions: older micro motor, newer STM and latest "Nano" USM), which sell for $350-$600, weigh just over 1 lb. and use 67mm filters.

There are three versions of Canon EF 24-105mm: original f/4L IS USM (not discontinued, but widely avail.), a cheaper f/3.5-5.6 non-L STM, and an f/4L IS "II" Nano USM. Those sell for $1000, $600 and $1100, respectively. They weigh between 1 lb 3 oz and 1 lb. 12 oz and all use a 77mm filter.

Quite frankly, none of the Canon 24-105s have impressed me all that much. Until recently Canon has offered an EF 28-135mm f/3.5-5.6 IS USM. It dates back to the film days, but actually holds it's own quite well against the 24-105s in terms of image quality and performance. It just doesn't seem as well built or sealed as the L-series (though it's actually proved to be just about as durable as the original)... BUT often sells for far less: around $200 used, or around $450 new before it was discontinued. Over the years, I've used four or five different copies of the EF 28-135mm and found them quite good. Never felt the need to spend more for a 24-105 that gave similar performance.

I have also used the much more expensive, larger and heavier EF 24-70mm f/2.8 USM (not stabilized, even the "II"). It's almost embarrassing, how close the 28-135mm is in terms of image quality... but sometimes I just need f/2.8!

If I were shopping today, for a top quality walk-around/standard zoom I'd probably buy the Canon EF 24-70mm f/4L IS USM. For about $1000 it's got nearly as good image quality as the 2X as expensive, heavier, bigger EF 24-70mm f/2.8L II (which is considered the best of all in terms of IQ alone)... Except the f/4L lens has IS (the f/2.8 doesn't) AND the f/4L can focus to an amazing .70X all on it's own (possibly making a separate macro lens unnecessary... for comparison the best the f/2.8L II can do by itself is .21X).

I'd probably usually pair that up with my EF 100-400L II (w/1.4X teleconverter, if using on full frame).... and possibly a 16-35mm f/4 IS USM... for a reasonable size & weight "hiking" kit. When I didn't need the "reach" of the 400mm, I'd substitute EF 70-200mm f/4L IS USM.

Canon has also made a bunch of different EF 28-90mm and 28-105mm over the years. I haven't used any of them, so can't comment.

Why do you think you need full frame? Just gotta ask, because there are a lot of "myths" about it. Unless you plan to make really big prints (upwards of 16x24"), or crop your images heavily (or both), you aren't likely to see a whole lot of difference from a recent, high quality APS-C model. For example, Canon 6D Mark II is 26MP... or for half the money an APS-C 80D is 24MP. Sure the full frame camera is a little better in low light conditions, and can give you a little more control over depth of field... but in some respects an APS-C camera is more versatile. In particular, there's a greater choice of lenses for use on an APS-C camera and the lenses you choose for it can be a lot smaller and lighter weight.