The module system solved real problems, most of which were the JDK’s own. Whether it solves yours depends on what you ship.

Libraries

A module descriptor is a genuine contract. It says what is public, keeps your internals unreachable rather than merely discouraged, and lets tooling like jlink produce something small. If you publish to other teams, write one.

Applications

An application usually already controls its own boundaries. Modularising one buys strong encapsulation you could have had from a build-level check, and costs you a long tail of reflective libraries that need opens clauses. Measure the benefit before paying that.