The amounts of data processed by applications are constantly growing. With this growth, scaling storage becomes more challenging. Every database system has its own trade-offs. Understanding them is crucial as it helps in selecting the right one from so many available choices.
Every application is different in terms of read/write workload balance, consistency requirements, latencies, and access patterns. Familiarizing yourself with database and storage internals facilitates architectural decisions, helps explain why a system behaves a certain way, helps troubleshoot problems when they arise, and fine-tunes the database for your workload.