A small set of cocktails has outlasted every fashion in drinking for over a century. What they have in common is structural rather than sentimental, and the drinks that disappeared usually failed for identifiable reasons.
Survival favoured simple ingredient lists
A drink with three or four components can be made anywhere, by anyone, from stock any bar already holds.
A drink requiring a specific proprietary liqueur dies with that product, and many did exactly that when producers closed or reformulated.
This is a filter on availability rather than on quality, and it explains why the surviving canon is so heavily weighted toward short ingredient lists.
Balanced drinks tolerate imprecision
A recipe that only works within a narrow margin will be made badly more often than it is made well.
The classics that persisted are forgiving, producing a drinkable result even when the measures are approximate.
A drink that is unpleasant when slightly wrong acquires a poor reputation regardless of how good it is when made correctly.
Templates propagate better than recipes
Drinks that follow a recognisable structure are easier to remember, easier to teach and easier to reconstruct from a half-remembered description.
The best-known classics are usually clean examples of a template, which is why they are used to teach the template itself.
A drink that fits no pattern has to be transmitted exactly or not at all, and exact transmission across generations is rare.
Written records decided what could be revived
The cocktail revival of recent decades worked from historic bar manuals, and only drinks that were written down could be recovered.
Reprinting of early manuals therefore had a direct effect on which drinks returned to menus, independent of how good they were.
Drinks that circulated only within a single bar or city left no record and could not be brought back at all.
Familiarity compounds
A drink that most bartenders can make is one most drinkers can order confidently in an unfamiliar bar, which sustains demand.
That demand keeps it on menus, which keeps bartenders trained in it, which keeps it orderable. The loop is self-reinforcing.
New drinks entering the canon almost always do so by being simple enough to enter that loop rather than by being the most interesting drinks of their era.
The same loop works in reverse on a drink that falls out of fashion, since a bartender who has never made it will steer an undecided customer elsewhere.
Recovery from that point usually requires a deliberate push from bartenders rather than demand from drinkers, which is how most of the revived classics actually returned.