Sequels, adaptations and continuations fill the calendar of major releases. The reason lies less in creative caution than in the arithmetic of marketing a film to a mass audience.
Awareness is the expensive part
A wide release must reach a very large audience within a short window, and the cost of doing so from a standing start is substantial.
An unfamiliar title has to explain what it is before it can persuade anyone to attend, which consumes most of the available marketing message.
A continuation skips that step. The audience already knows the world and the characters, so the campaign can spend its effort on the date instead.
Risk is concentrated in the opening days
Cinema economics turn on the first weekend, because screen allocation for subsequent weeks is adjusted according to that performance.
A soft opening reduces showtimes immediately, which reduces the following weekend further. The decline compounds quickly and is difficult to reverse.
Familiar titles produce more predictable openings. Predictability is worth a great deal when a single weekend determines the shape of the whole run.
Financing prefers a known pattern
Large films are funded through combinations of studio capital, co-financing and pre-sales to distributors in individual territories.
Those counterparties commit before the film exists, using the performance of comparable titles as their basis. An established property supplies exactly that comparison.
An original film offers no such reference, so it either carries a smaller budget or requires backers willing to accept a wider range of outcomes.
Revenue extends well beyond the cinema
A recognisable property continues to earn through licensing, merchandise, theme park attractions, games and streaming rights long after the theatrical run.
Those revenue lines depend on the audience's ongoing familiarity, which each new instalment refreshes.
Viewed that way, the film is partly an investment in maintaining the property, and the calculation differs from judging it as a standalone release.
The strategy carries its own limits
Audiences do tire of a property, and the decline is usually visible in the gap between opening weekend and total takings rather than in the opening itself.
Studios respond by resting a property, changing its tone, or restarting it, since the awareness that makes sequels attractive survives even a poorly received instalment.
Original films continue to be made, but they increasingly arrive at a scale where a disappointing opening does not threaten the studio's year.