The OP raises some truthful concerns about vacation and travel photography. I think the big pro DSLR with a multi-lens setup is just entirely impractical.
iPhones might be decent, but they're still cell phones and inferior in many ways.
The ideal setup for travel, in my opinion -
A refurb Nikon D3200 or D3300, with a used 18-200mm.
This is one of the smallest and lightest DSLR's that still packs a seriously good sensor, and perhaps the best all-purpose lens that gives you everything from wide angle to telephoto. It is not as large or heavy as the 18-300. This is a very reasonable size/weight combo that does it all for travel. It also doesn't break the bank and if it gets destroyed or stolen, isn't as devastating as losing pro gear.
That covers virtually all scenarios except low light. For that, a $150 35mm 1.8 does the trick. Small and light. That total "kit" is not unreasonable to lug around. If you own Canon gear, it doesn't matter about interchangeability, because this would be "as is" kit for travel. if you can give up low light and are willing to crank up the ISO - skip the 35mm. High ISO shots with a DSLR are going to be cleaner and better than any cell phone. With just that body and that lens, it really is a small, light and easy platform. Use the simple strap and call it good. At best maybe a thin holster style case in case it rains.
If that is too much - then Powershot or other point and shoot cameras are the next logical step. These are vastly superior to cell phone cameras. But again, if that DSLR is too much, then a powershot is probably a no-go also as at this point, the photographer just isn't willing to carry or use anything extra other than a cell phone.
My opinion is, anything is better than a cell phone.
One thing I've learned is, on vacation or traveling, you just can't get the super high quality photography you think you want. Quality landscapes or scenery requires time, patience and good step. Who has that on vacation? Unless you're a loner and this is your main hobby and enjoyment while traveling, it's not going to work out that way.
Almost like an event photographer, you need a kit that is fast and will adapt to any scenario. Yes, there is always compromise. But that compromise isn't nearly the hit in image quality you'd take settling for a cell phone.
Sure, there is no way that that Nikon setup is going to come close to what my 5D3 can do with a 70-200 II or 24-70 II. However, I'm not going to bring that camera or those lenses. And the Nikon (or Canon equivalent) will be many, many times better than a lousy cell phone.
;D