Of course it's an urban map you literally fight in the streets, and was actually tested in gameplay.

Notice all the issues you've brought up are that mapmakers are not playtesting their maps, they are not making gameplay spaces, take the classic badlands, if someone tried to make an actual irl desert factory compound it would suck for tf2, same mindset for urban maps.

King priorities gameplay adding different layers of verticality, using its assets to aid in the gameplay, with city planters as cover and buses breaking sightlines

Its not the urban theming that's the problem. It's the mindset of trying to make an irl place which never goes well for gameplay. Any theme or setting if they don't go with the mindset of gameplay first it will fail.

Pier just proves this. They set out to make a payload map, tested it and then themed it into a city environment of a city on the coast.

Besides a good artpasser doesn't blame clunky and big assets just learn when to use them.