Comedy built on references to specific people, products or events becomes unwatchable far more quickly than comedy built on constructed situations. The difference is where the humour is stored.
A reference outsources its setup
A reference works by pointing at something the audience already knows, and the audience supplies the context from memory.
That makes it extremely efficient. A single name can carry an entire premise without a word of explanation.
It also makes the joke dependent on knowledge held outside the work. When that knowledge fades, nothing inside the joke replaces it.
Constructed jokes carry their own materials
A joke that builds its premise on screen contains everything needed to understand it, so a viewer arriving decades later receives the same information as the original audience.
Farce, character comedy and situational humour all work this way. They may date in style, but the mechanism still functions.
This is why very old comedy can still work while comedy from a few years ago frequently does not. Age is a poor predictor of durability; self-sufficiency is a good one.
Shared knowledge decays unevenly
Some references survive because their subject remains famous, while others depend on things that were briefly universal and then disappeared entirely.
A writer cannot reliably predict which is which, because at the time of writing both feel equally well known.
The failure is therefore invisible during production and only becomes apparent once the audience has changed. By then the work is finished and the joke cannot be repaired without rewriting the scene around it.
Fragmentation shortened the window further
Broadcast schedules once produced genuinely common knowledge, since a large share of a population watched the same things.
That common ground has thinned considerably, so a reference now reaches a smaller group even at the moment it is made.
Writers respond by referencing older material with a longer half-life, which is why a great deal of contemporary comedy points backwards. Material that has already survived a few decades is a safer bet than anything currently everywhere.
Parody sits somewhere between the two
A parody that recreates the form of what it targets teaches the audience the original as it goes, which gives it a longer life than a passing reference.
Where the parody only names its target, it decays at the same rate as any other reference.
The distinction is whether the work does the explaining or expects the audience to arrive already knowing, and that choice determines how long the comedy lasts.