Trends are usually discussed at their peak and then treated as having disappeared. What actually happens is a long decline through the market, and the stages of it are fairly consistent.
Saturation is the turning point
A style spreads because it signals something: awareness, taste, membership of a group that noticed it early.
Once enough people wear it, the signal stops working, because a thing everyone has cannot distinguish anyone.
The people who adopted earliest move on at exactly that moment, and their departure is what marks the peak rather than any drop in sales.
The style descends through price tiers
By the time a look reaches saturation at mid-market, it is only beginning at the lowest price points, where lead times are shortest and volumes largest.
Each step down simplifies the garment, since a lower price cannot support the fabric, the construction or the detail that defined the original.
What arrives at the bottom of the market is a recognisable outline of the trend, which is why the version most people encounter last is the weakest one.
Distinguishing details are stripped first
The elements that made the style specific, such as an unusual seam, a particular proportion or a distinctive fastening, cost the most to reproduce.
They are removed one at a time as the garment moves down in price, until only the silhouette and colour remain.
At that point the item is generic, and it stops being read as part of the trend at all, which is what disappearance actually looks like.
Some elements survive by becoming ordinary
Not everything descends and vanishes. Certain features are absorbed permanently into what clothing simply is, and stop being noticed.
Stretch content in denim, technical fabrics in ordinary outerwear and sneakers worn outside sport all entered as trends and became defaults.
The test is whether the feature solved a practical problem alongside a stylistic one. Those tend to stay; purely stylistic ones cycle out.
The decline creates the conditions for revival
A style that has become generic eventually becomes invisible, then dated, and finally distant enough to be looked at freshly.
The version revived is rarely the mass-market one that ended the cycle. It is the original, specific version, retrieved from archives and images.
This is why revivals so often look better than anyone remembers the trend being. The remembered version is the degraded one, and the revived version is not.