Two years might be too short.

The overwhelming majority of works have an effective commercial life of less than ten years.

Present-value analysis further reduces the individual benefit of long-lived copyright. That is warrented in only a minuscule fraction of all works.

(There are roughly 1 million books published in English annually, of which ... ten make the top-ten best-seller list. The situation gets worse if we consider this a conservative estimate, or include all other copyrighted works created in a year ... every one of the billion or so items posted to social media accounts on a near-daily basis is protected by copyright. Few if any of those have any real commercial value. The fraction of works fostered vs. works encumbered by copyright is parlous small.)