Yes I agree that versatility and shots greatly "trump" IQ for this case and probably most cases.
For me I find that I shoot mostly in the 16 or 18mm to 30mm rage (I don't shoot much at 14mm partially becaus I think that's the weakest part of the 14-30 and some of the distortion at 14mm can be rather extreme, more extreme than I'd like actually, but 16-18mm is usually plenty wide for me). Now that being said, I guess the minor "gaps" on both ends (in favor of a much lighter smaller lens) does make sense and most of my shots are going to be probably stepped down a bit probably to around f/5.6 to f/11 as most will be travel-type, or architectural photos. So I can see using the 20mm (I may still bring both with me on the trip though just so I have the options). I don't know if I could go on a such a trip without a wide angle, but I may challenge myself one day to shoot only shoot wide angle with the 20mm and limit myself to shots only at that FL. And really between 20mm and the 24-? I don't know that I'd be missing out that much not having the 14-30 with me for the day. I mean if I'm photographing ceilings /domes in a church then I might either have to crop out some stuff or skip some shots (those are instances where a 14-30 might be useful though).
My last trip where I had an opportunity for a city walkabout, I brought only the 40 f/2 and 28 f/2.8 on my Z6 to keep it light and compact. As someone who rarely shoots much wide angle for fun, I was shocked when I got back to the hotel to realize I had never even taken the 40 out of my sling. I also noticed I didn't miss having the zoom (24-120) - which I typically take on that type of adventure - as it was a fun "challenge" to find photos from that single field of view, rather than have a massive field of view range for a huge variety of shots anywhere I happened to be standing.
In general, I find that I come back with more complete photo sets/collections in terms of a style and theme when I go on these types of walks or adventures with one or two primes compared to the zooms. It's happened with my 28, 40, and 50 on independent trips, and those sets are some of my favorites even though I have some killer zooms.
It's sort of like when I was in school and we'd have to write a paper in a certain style and length on a specific topic, rather than the teacher just telling us to write a paper about whatever we wanted with little to no direction. Both exercises had a purpose, but the paper with rules or guidelines often resulted in a more concise, focused, and complete piece or story.
I'm not suggesting you don't bring a zoom, just that there are multiple ways to think about a trip like this in regards to gear. Considering an end goal of some type might make it more interesting and less scattered if that mindset works with your personality type.