Undeniably, the landscape of modern commerce has been indelibly etched by the advent of Ecommerce. This paradigm shift in how we conduct business has necessitated the evolution of various software tools to manage the complex operations involved in Ecommerce. Fulfillment software, being a crucial component in this ecosystem, is no exception. As we traverse through the 21st century, it is essential to consider the future trajectory of Ecommerce Fulfillment Software (EFS), its predictions, and the emerging trends.

To comprehend the future of EFS, one must first grasp what it represents. EFS is essentially a technologically empowered system that aids in the management of order fulfillment processes. From inventory management, order picking, packaging, shipping to returns management, EFS streamlines it all. The relevance of EFS is underscored by the need for efficiency, cost-effectiveness, and scalability in Ecommerce operations.

From an economic standpoint, the growth in Ecommerce is a fait accompli, a foregone conclusion. Data from eMarketer projects that worldwide Ecommerce sales are expected to reach $4.9 trillion by 2021, a staggering 265% growth rate from 2014. This surge inherently implies an increased demand for EFS, driving its future trends and innovations.

We're circling an era where artificial intelligence (AI) will become an integral part of EFS. The exploitation of AI algorithms in EFS will optimize decision-making processes, enhancing sorting, picking, packing, and shipping. AI will also facilitate predictive analytics, a proactive approach that could dramatically reduce return rates and improve customer satisfaction. The staggering rise in machine learning, a subset of AI, portends a future where EFS may become autonomous, with minimal human intervention.

Blockchain technology, a decentralized ledger system, is another revolutionary technology that is predicted to infiltrate EFS. Blockchain could potentially instigate a new level of transparency and security in Ecommerce operations. From tracing product origins to verifying transactions, blockchain can mitigate fraudulent activities and foster trust in Ecommerce transactions.

On a socio-economic level, the growing trend of 'glocalization', a concept that combines global and local considerations, will impinge on EFS. With the world becoming a global marketplace, EFS will need to adapt to localized regulations, cultural nuances, and diverse payment methods, all while maintaining a global standard of operations.

However, these technological advancements are not devoid of trade-offs. The implementation of AI and blockchain in EFS would require hefty investments in infrastructure, personnel training, and data security. While these technologies promise efficiency and transparency, businesses must carefully assess the return on investment and potential risks involved.

In terms of regulations, the General Data Protection Regulation (GDPR) in the European Union and similar laws worldwide pose challenges to EFS. Balancing data utilization for AI and maintaining privacy will be a delicate act to perform.

Advancements in EFS also bring into focus ethical issues related to job displacement due to automation. Although automation can boost efficiency and reduce costs, concerns about its impact on employment opportunities cannot be discounted. Therefore, policymakers and businesses need to strike a balance between technological advancement and social responsibility.

In summary, the future of Ecommerce Fulfillment Software is an intriguing blend of promise and challenges. As the Ecommerce landscape evolves, so too will the software that supports it. Innovations in AI and blockchain are set to transform how we manage order fulfillment, but businesses must be cognizant of the associated costs, regulatory challenges, and societal impacts. The key to navigating the future of EFS lies in embracing technological advancements while maintaining a steadfast commitment to holistic, sustainable growth.