Cities were, for a long time, designed mostly around efficient movement and dense building, with green space treated as decoration squeezed in wherever room happened to remain. That priority has been shifting, with more cities now treating trees, parks, and planted verges as functional infrastructure rather than an optional afterthought.
The practical case is fairly direct: green cover cools a hot street noticeably, planted areas absorb stormwater that would otherwise overwhelm drains, and even a modest strip of vegetation along a road can measurably improve air quality nearby, all while requiring far less maintenance than most built infrastructure demands.
The result, where it has been taken seriously, is a city that feels different to move through day to day: shaded footpaths, birdsong along a commute, a park within easy reach of most homes, each one a small, cumulative sign of a landscape being deliberately reshaped rather than merely tolerated. None of it happens by accident, since every one of those small green details reflects a deliberate choice made somewhere earlier in the planning process.