Credits at the end of a feature now run for many minutes, far longer than they did a few decades ago. The growth is contractual and structural rather than ceremonial.
Credit is a negotiated entitlement
For a large share of the people who work on a film, the right to appear on screen is written into an agreement, with the wording, order and placement specified.
Guild and union agreements set out who must be credited and in what form, and those provisions are enforceable rather than a matter of the producer's discretion.
Because credit is an entitlement, it cannot simply be trimmed for running time. Removing a name is a breach, not an editorial choice.
Modern production employs far more people
Visual effects work in particular is distributed across multiple vendors, each with its own artists, supervisors and coordinators, and all of them appear.
Effects-heavy features accumulate hundreds of such names, which is the single largest contributor to the growth in credit length over recent decades.
Second units, additional photography and reshoots each bring further complements of crew, and a production that shoots in several countries carries local crews in each.
Order carries meaning of its own
Position in the credits signals seniority, and the sequence is negotiated with care, particularly at the head of the roll and among the principal cast.
Shared cards, the size of type and whether a name appears alone are all points of negotiation, because they are read as statements about standing.
The same logic governs the opening titles, which is why some films now carry almost nothing at the front and push everything to the end.
The tail is not only crew
Music licences require specific acknowledgements, and each cleared track carries its own block naming writers, publishers and performing rights bodies.
Locations, equipment suppliers, tax incentive authorities and financing entities all appear under obligations attached to the support they provided.
Insurance and legal disclaimers close the roll, and their wording is fixed, which is why the final cards look identical across otherwise unrelated films.
Scroll speed is constrained
Credits must remain legible, which sets a maximum speed, and that speed multiplied by the number of cards determines the running time directly.
Studios have experimented with wider columns and denser layouts, but legibility standards and contractual size requirements limit how far compression can go.
The practice of placing an extra scene at the very end works with that constraint rather than against it, giving the audience a reason to sit through the roll.