Adoption is designed in from the start, not added after launch. The most common reason design systems fail is that teams build them in isolation and then expect others to use them.
We involve consuming teams early so the system reflects real needs, not assumptions. We make the system easier to use than building from scratch, so adoption is the path of least resistance rather than an imposed mandate.
We document everything thoroughly and establish governance that gives teams a voice in how the system evolves. When people feel ownership over the system, they use it and contribute to it.